The TARDIS crew are as yet unaware of the threat posed to them by the Daleks and their time machine. Instead, they pass time in various pursuits. Vicki, however, is having a bad day, bored and aimless. She succeeds in irritating the Doctor as he works on the Xeros' Time/Space Visualizer, Ian as he reads a "farfetched" book on aliens, and Barbara as she attempts to make a dress for Vicki.

All that is forgotten, though, when the Doctor finishes his work. As he gives a baffling explanation of the function of the Visualizer, Vicki takes a moment to simplify if for the others. This is a sort of time television, which can see any event in the history of the universe.

Everyone gets a chance to choose a historical moment to look at. Ian sees Abraham Lincoln delivering the Gettysburg Address. Barbara sees Queen Elizabeth I having an audience with William Shakespeare, and the genesis of the idea for his play Hamlet. And Vicki tunes in to 1965 to see the Beatles perform "Ticket to Ride". Ian and Barbara are surprised that she knows of them, but she explains that they are still well known in Earth's far future, only Vicki was unaware that they played "classical music"!

The demonstrations end when the ship lands. Everything looks good on the instruments, so the Doctor opens the doors. Outside, it's nothing but arid desert, scorched by quickly-moving twin suns. Vicki sees some strange formations on top of a ridge some distance away. She heads off to check them out, followed by Ian, who takes a "TARDIS magnet" with him to find their way back.

The formations appear to be seaweed, which Ian thinks is impossible. They also find a trail of what appears to be blood in the sand, which Vicki is keen to follow. As they move off, a tentacle rises up from the sand where they were.

Meanwhile, the Doctor and Barbara do some sunbathing. Barbara is attracted back inside the ship by the sound of the Visualizer, which has not been shut off. She sees on it a "broadcast" of the Daleks preparing to give a report. The Doctor enters and hears to his horror the Daleks planning to follow "the enemy time machine" to its landing place in the Sagarro Desert on the planet Aridius. Dalek assassins will take their time machine, find the Doctor and his companions, and exterminate them. The Doctor and Barbara watch a group of Daleks embark and dematerialize.

The Doctor quickly realizes that these events happened in the past. The Daleks may already be here. They must find Ian and Vicki and leave immediately.

Tiring from their walk, Ian and Vicki take a rest as the "blood" trail ends. In the sand, they find a large metal ring. At first, Vicki is reluctant to disturb it for fear of what it might unleash. However, she decides they should and Ian pulls it loose. At first, nothing happens and they prepare to leave, but then an ancient trap door creaks open in the sand. Vicki and Ian go down inside to have a look.

The Doctor and Barbara have had no luck locating the others. What's worse, night has fallen and the wind has begun to pick up, covering all tracks including their own. They decide to return to the TARDIS, not entirely certain of the direction.

Ian and Vicki go deeper into the cavern below, only to have the trap door close behind them. They are trapped. What's worse, another tentacle looms out of the darkness.

On the surface, the wind has become a full-blown sandstorm. The Doctor and Barbara are unable to find the ship. With no other shelter, they simply hunker down and cover themselves with their clothing the best they can. There they stay all night.

When dawn breaks, the sandstorm is over, but they find that the entire landscape has changed. The ship has been buried in sand and they have no way to locate it as Ian has the TARDIS magnet. The Doctor hears something and forces Barbara to hide behind a sand dune.

Two more Daleks arrive to join the first. They are searching for the TARDIS, and they detect its presence under the sand in this area. It must have been buried in last night's storm. They will fetch a seismic detector to locate it precisely before digging can begin. The rest of the Daleks will find the travellers and exterminate them. Barbara and the Doctor move off in order to keep clear of the Daleks, but they do not get far when they meet up with two strange humanoid creatures.

Ian and Vicki come face to face with one of the tentacled creatures in the underground cavern. They retreat into the catacomb, only to find another one waiting for them. They are trapped in between.

A Dalek patrol finds footprints belonging to Barbara and the Doctor, but before they can follow, they detect a being approaching. The Daleks exterminate it on site - an Aridian native, of no importance.

The Doctor and Barbara have been befriended by two of the Aridians, called Malsan and Rynian. They are amphibian-like humanoids, looking very out of place in this desert world. They explain that this planet was once covered by a vast ocean and that they lived in a giant city under the sea. However, the suns have come nearer over the last 1000 years, drying up the water. Most of the creatures of the planet died as a result; only themselves and the Mire Beasts survived. They lived in the slime at the bottom of the ocean, eating other sea creatures. When the water dried up, they invaded the city to feed on the Aridians. The only way to keep them out is to wall off the invaded portions to keep them contained.

Worried by all this danger about, Barbara inquires about Ian and Vicki and asks for help in finding them. Malsan believes from her information that they may have entered the city through the Taltarian airlock. However, that section of the city is soon to be blown up in order to destroy the Mire Beasts trapped there. Alarmed, Barbara urges them to help. At first, the two Aridians are sceptical, but they offer to try and reach the airlock in time. However, they only manage to get within sight of it when it explodes.

Ian and Vicki are near the explosion site. The collapsing walls and stones kill the marauding Mire Beasts, but Ian is knocked unconscious and Vicki is badly shaken. She makes him comfortable and runs off to try and find help.

Malsan and Rynian bring Barbara and the Doctor to another airlock, offering them rest and food before continuing their search. The Doctor thanks them but also warns them of the Daleks and the threat they pose. He doesn't want the Aridians mixed up in this dangerous business.

The Daleks pinpoint the TARDIS with their seismic detector. They will take some Aridians prisoner and force them into slave labor to dig it out.

The Doctor and Barbara enjoy their refreshment, but Barbara is still worried about Ian and Vicki. The Doctor is sure that they have escaped both the Mire Beasts and the explosion. He urges her to sleep and conserve her strength for the work that lies ahead. Shortly, Malsan and Rynian arrive to check on them. The Doctor asks about a walled portion of the room, and Malsan tells him it leads to an area infested by Mire Beasts. It was blocked off to protect the rest of the city.

Malsan also brings bad news -- the Daleks have found out the travellers are being sheltered here. They have ordered them handed over or they will destroy the remains of the city. The Doctor thanks him for the information and proposes to leave immediately without the Aridians' further involvement. However, Malsan says that they must hand over the Doctor and Barbara, not let them go to try and escape. They will be held as prisoners until the deadline is up.

Later, the digging in the desert is completed and the TARDIS has been freed from the sand. The Aridian laborers are callously exterminated. But the ship resists Dalek firepower. A guard is put on the ship, awaiting the recovery of the time travellers.

Barbara awakes just as Malsan returns. The elders have agreed to the Daleks' demands to hand over their prisoners. The Daleks have promised to leave the planet unharmed if this is done by sunset. The Doctor does not blame them for making the decision, but he also knows they have two hours before the hand-over, during which time anything could happen.

Unseen by anyone in the room as they talk, one part of the crudely-built wall leading to the infested section of the city begins to bulge outward ominously.

Elsewhere, Ian comes to. His head hurts, but otherwise he is unharmed. There is no sign of Vicki and so he hurries off down the only open corridor, calling after her.

Vicki, however, has been found by the Aridians, who bring her to the Doctor and Barbara. She tells them about Ian and the explosion. She also tells them that she saw the TARDIS through an opening in the tunnel roof. It is not far away. The Doctor and Barbara's spirits lift considerably. However, Malsan arrives as the deadline has come. Before he can take them away, though, a Mire Beast bursts into the room through the weakened wall. Barbara is nearly caught, but instead Malsan takes her place when he tries to rescue her. He is devoured by the creature. In the confusion, the travellers escape into the tunnels.

At the opening which leads to the TARDIS, they find Ian waiting for them. The reunion is joyous but brief. There is still a Dalek guarding it. But Ian has an idea. Using the Doctor's coat and Barbara's cardigan (again), he fashions a false ground cover, which he tops off with sand. The four travellers then taunt the Dalek guard, which fires at them with no luck. When it approaches their hiding place, it travels over the false ground and tumbles into the hole.

The travellers celebrate their victory over the Daleks, immensely pleased with themselves. That is, until a signal begins bleeping from the console. The time path detector is registering something following them through time and space. It is the Daleks.

In pursuit, the Daleks lock a tracking device onto the TARDIS. They calculate that they are only 15 minutes behind, and closing. The execution squad prepares to disembark.

The Doctor has been unable to shake the Daleks off. If they can't elude them, they must stand and fight. The Doctor informs the others that the ship's computers require 12 minutes to reorient and repower themselves upon landing. That time will be vital when they land again. And the slowing of the time rotor's movement indicates that this will occur shortly.

New York City. On top of the Empire State Building, a group of tourists hear the spiel of a very bored tour guide pointing out facts about the building and the city. One of them is a curious young man Alabaman called Morton Dill. As the group heads off to the north side of the building, Dill stays behind to catch his breath and to look over the city.

When he turns round, he finds to his amazement that a tall blue box has simply appeared. Barbara exits the TARDIS and Dill is taken aback, but he greets her politely. Barbara realizes this is Earth, and Mr. Dill - with a bit of prompting - informs her that the year is 1966.

Vicki comes out and is greeted, also politely, but with even more surprise. Dill's confusion grows when he hears Vicki describe this as "ancient New York", a place that was destroyed in the Dalek invasion. When Ian and the Doctor exit the ship, Dill is convinced this is some kind of trick. Ian realizes that this is too confined a space in which to fight the Daleks, and the group turns to go back inside. Dill is sceptical they can all fit inside, as this is all obviously some type of Hollywood movie trick. He's sure he's seen something like it before - in a chase film.

The Doctor dismisses him and returns to the ship. Dill pursues the point, pounding on the door. However, when he turns to retrieve his movie camera, the ship disappears. It is replaced by the Dalek time machine, which appears in the same place.

Dill is fascinated. However, he is heartily amused at the sight of a Dalek, which he describes as "ugly-lookin'." He tries to shake its gun stick in place of a hand and the Dalek moves in menacingly. He mentions the "other movie people" and tells the Dalek that they just left. The Dalek returns to its ship, dematerializing just as Mr. Dill turns once again to get his camera. When he turns around, he is alone, thunderstruck. He tries to figure out where everyone has gone, going so far as to start stamping on the floor looking for a hidden trap door. When the tour guide returns, he is convinced Dill is crazy and goes to fetch a policeman.

On board the TARDIS, the Doctor begins work on a machine with which he hopes they can fight the Daleks. However, when the TARDIS indicates an imminent landing, he is upset as the weapon is nowhere near ready.

On board a sailing ship, the captain, Briggs, laments their situation to his first mate, Mr. Richardson. They are making poor time and are now becalmed off Santa Maria in the Azores. He leaves Richardson in charge and goes below.

The TARDIS materializes on board the ship. Barbara sees where they are on the scanner and gets very excited. She loves sailing ships and must go out for a quick look, despite Ian's warnings. But she is immediately found and caught by Richardson, who believes she is a stow-away.

Ian and the Doctor discuss their predicament, realizing what they need is some large, open space in which to fight the Daleks. Ian heads out to retrieve Barbara and Vicki, who has followed her out.

Richardson starts to take Barbara below decks when he is clubbed on the head by Vicki, hiding on the deck above. When the women hear someone else coming, Vicki hides, hitting the newcomer hard just as he reaches Barbara. However, it is Ian she has struck, and he nearly topples down the stairs as he fall unconscious. Vicki and Barbara haul him back to the ship. Richardson wakes up just as the TARDIS dematerializes.

Richardson calls Captain Briggs and tells him confusedly about the stowaways. He believes it is the White Terror, but the Captain dismisses this as only a sailor's superstition. The Captain organizes his men into a search.

The Dalek time machine materializes on the ship amid the search, convincing the sailors that the White Terror has indeed come. Many of the men simply jump overboard in their panic. Some attempt to fight, but they can do nothing against the Daleks. Once the sailors are despatched, the Daleks are free to search for the TARDIS, but the time machine is obviously not here. One sailor, straggling from below decks, emerges and sees the Daleks. One of the creatures tries to question him, but he backs away until he falls in. The Dalek, not seeing the edge of the deck, also falls over. The rest of the Daleks reembark, leaving the ship, the Marie Celeste, to drift empty across the sea.

A dark and spooky house, filled with strange noises and deep shadows. Thunder rumbles outside. There is an air of menace about it. It is here that the TARDIS lands, near the foot of an open staircase. The Doctor and his companions emerge are look around. Ian is initially pleased, citing the strong walls and open space as ideal for fighting Daleks, as well as the presence of the stairs. However, when a flurry of bats come out of the rafters, they all begin to reassess. The Doctor and Ian elect to explore upstairs, quickly, but a second flurry of bats encourages the girls to stay downstairs.

Barbara and Vicki steel themselves and start to explore the ground floor, beginning with the fireplace. It looks like a sinister face, a feeling which is enhanced when two large eyes open above the mantel, frightening the girls away. Nearby, they find a large box. When they start to open it, an evil laugh reverberates to the room. Gingerly, they open to lid to find nothing, and they are greatly relieved. That is, until a skeleton drops down in front of them from the roof, frightening them further.

Ian and the Doctor find themselves overlooking what appears to be a laboratory. The Doctor is intrigued by something under a cover on a table. He and Ian start to investigate, but are chased away by what appears to be a Frankenstein monster which jumps up from the table when they approach.

Vicki and Barbara come face to face with a strange man dressed in a black suit and cape, with fangs protruding from his mouth. He introduces himself as Count Dracula, then calmly disappears through a secret door. Baffled, Barbara investigates the wall where he vanished. When she turns back around, Vicki has disappeared. Suddenly, she is taunted from above by a ghoulish female figure who screams out in anguish and torment. Startled, Barbara falls against the wall and onto a roundabout, which takes her away with a scream.

The Doctor and Ian make their way to the top of the stairs, nearly frightening themselves in the process. They are both struck by the familiarity of their surroundings - the Doctor says it is just like a nightmare. He expounds a theory that this is not really space and time, but a world where nightmares have become reality. Ian is sceptical, but hopes it is true as the Daleks could never follow them here. Emboldened, they hurry downstairs, unleashing another flurry of bats. They discover the girls missing and find no trace. They head back upstairs to look for them.

The Daleks arrive on the main floor, next to the TARDIS. They are on Earth and the travellers are still here. Victory is imminent. They spread out to search while 1 Dalek stays on guard at the time machine.

Ian and the Doctor return to the laboratory and reluctantly go into it to search. A Dalek appears and threatens them. Ian pulls a switch and a grille falls in front of it. He and the Doctor run like mad. The Frankenstein monster rises from the table and pulls the switch, opening the grille, and then attacks the Dalek.

Ian and the Doctor hurry down the stairs and run straight into Barbara and Vicki, who have freed themselves from the secret passage. The reunion is again short-lived as the Dalek guard sees them. Before it can fire, Count Dracula appears behind the Dalek and it turns to face the more immediate threat. Ian, Barbara, and the Doctor take advantage of the distraction and dash into the TARDIS. Vicki, too frightened to move, hangs back. When she finally does turn to move, she is trapped by another group of Daleks. Unbeknownst to her fellow travellers, she is left behind in the house as they dematerialize.

The Daleks order her killed, but the appearance of the Frankenstein monster gives them another threat to handle. It attacks the nearest Dalek and smashes it to pieces. Dracula and the female ghoul also return, and the Daleks fire wildly at the creatures. In the chaos, Vicki runs into the Dalek time machine, knowing it to be her only hope of escape. The Daleks, losing the fight, retreat into their machine.

Ian and the Doctor discuss the Doctor's theory about the location of the house. The Doctor insists it was a place created of human nightmares, but Ian is certain there is another explanation.

Indeed there is. As the Dalek time machine dematerializes, it becomes clear that it was a spook house created for the now-cancelled "Festival of Ghana 1996".

The Doctor continues working on his weapon for fighting the Daleks, a delicate-looking box with extra wires and switches seemingly placed on at random. Both he and Ian know it is their only hope. They need only choose their battleground. Barbara brings much-needed refreshment, and they all notice at once Vicki's absence, each one having believed she was with one of the others.

On the Dalek ship, they track the TARDIS to its imminent landing site - the planet Mechanus. Meanwhile, a machine called a reproducer is readied for use. It is programmed to produce a replica of the Doctor. Once details are entered into the computer, the machine is activated and the Daleks move off.

Vicki enters as the Daleks leave, searching for a radio transmitter. She finds one and tries to contact the TARDIS, with no response. Sensing some evil behind her, she checks out the reproducer chamber and sees inside a shadowy humanoid figure that looks somehow familiar...

The Doctor takes full blame for leaving Vicki behind. Ian and Barbara try to find out if they can return to get her, but the Doctor knows it would take months of work to repair the ship enough to attempt it. With the Daleks on their track, they will never have that time. Ian realizes that the Dalek time machine is fully-functional. If they can liberate it from the Daleks, they could use it to go after Vicki. It will be dangerous, they agree, but it is their only choice.

Vicki tries again to raise the TARDIS on the radio, but to no avail. She hides quickly as the Daleks return. The enemy time machine is landing on Mechanus, and they will arrive there in 4 minutes. The robot is now complete, its power cells fully charged. Vicki watches from hiding as a perfect replica of the Doctor emerges.

The Doctor, Ian, and Barbara survey their new landing site on the scanner. It is swampy, open, and full of lush vegetation. It seems ideal for fighting the Daleks. They take their weapon and go outside to investigate further.

The Doctor and company find Mechanus dark and dank, full of strange noises and even stranger vegetation. They come across a very tall tree-like structure with a mushroom-shaped top and tendrils hanging down. Not sure if it is a plant or a fungus, they move in to investigate. They determine it is a living fungoid...as it bends to attack them. Turning to retreat into the TARDIS, they find that more have moved forward to block their way. They are rootless and can move! But before the fungoids can surround them, a bright light shines down from far above, and the fungoids retreat, obviously averse to the light.

The travellers are grateful for the light, but wonder who switched it on. The mystery deepens when Ian realizes that the lights are set out in some sort of corridor far into the distance. They set out following the lighted path.

The Daleks exit their time machine with only one thought: elimination of their enemies. They are to treat all forms of life here as hostile and kill on contact. The robot Doctor is brought out and sent after the time travellers, whom the Daleks have detected moving ahead of them. They fan out and follow behind.

Vicki manages to slip out of the time machine and attempts to follow the Daleks at a safe distance. She is hampered by the fungoids, which attack her instantly.

The Doctor, Ian, and Barbara reach the end of the corridor of lights. There they find a very small dead-end cave. They wonder why the lights lead to a dead-end, but find no answers. Instead, they find a cache of rod-shaped light emitters, obviously used to fight off the fungoids. Ian and Barbara are sure they now have all they need with which to fight the Daleks, but the Doctor tells them they cannot use his weapon in an enclosed space. Fearing that the Daleks will find and follow the corridor of lights, thus trapping them in the cave, they set about trying to turn them out.

Vicki has proven more mobile than the Daleks and has reached the TARDIS ahead of them. She is elated and bangs on the door for the others to let her in. But there is no answer. She is attacked by another fungoid, but it doesn't move very energetically in the light. She moves on down the corridor of lights. Unbeknownst to her, Ian, Barbara, and the Doctor have found the lights' control cable and rip it out, the lights go out. Vicki is immediately attacked by a vigourous fungoid. She screams in terror and passes out.

Ian and the others hear the distant scream. Barbara is sure it is Vicki. Ian and the Doctor hurry out to investigate, leaving Barbara to stay and protect the machine.

Meanwhile, the Daleks are unconcerned about the lack of lights. Their perceptors indicate much movement in the direction the lights were leading. They will follow these readings instead. As they move out, a fungoid attacks, but it easily destroyed.

The Doctor and Ian find Vicki unconscious beneath a fungoid. They quickly figure out how she got here and that that means the Daleks are here too. They pick her up to return to the cave.

In the cave, Barbara is startled to see the Doctor return so quickly. He informs her that Ian is dead, killed by the fungoids. When she refuses to believe this, the robot Doctor leads her off to see for herself.

Returning to the cave, Ian and the real Doctor find it empty. Ian goes outside to look for Barbara while the Doctor tends to Vicki. She comes to and reacts in terror when she sees the Doctor, hiding in a corner of the cave. Ian returns and calms her down. She comes to realize that this is the real Doctor. She tells them all about the robot and its mission. They realize that the robot must already have Barbara. Ian hurries out to find her, the others trailing behind.

Barbara is annoyed when the Doctor seems to lead her in circles. Behind her, she hears Ian calling her name and tries to drag the Doctor toward him. Suddenly, the robot Doctor grabs her and tries to kill her. Ian arrives and stops him, only to have the robot hit him and run off.

Ian and Barbara come face to face with the robot just as the real Doctor and Vicki arrive. Each Doctor accuses the other of being the robot, and Ian attempts to defeat one of them. He eventually gets the upper hand and the other Doctor urges him to destroy the "impostor" with a rock. The girls realize Ian has the wrong one and urge him to stop.

The robot knocks Ian aside with his walking stick and the two Doctors engage in a duel with their sticks. The real Doctor triumphs, removing the robots control circuit and disabling it.

The Daleks find the TARDIS in the jungle. They are again attacked by a fungoid. There is not sign of the travellers, and the robot has stopped registering on their instruments. However, the darkness, the poor terrain, and the prevalence of fungoids here hamper their search. They decide to stop, planning to resume at daybreak.

The TARDIS crew return to the cave. Despite the setbacks, they are all glad to be together again and in one piece. The Doctor, exhausted by all the exertion, enters the cave to rest with Barbara and Vicki. Ian stays on guard outside. As the three sleep, a camera lens on a long boom lowers from the cave roof and surveys them...

At daybreak, the Doctor awakes first. Emerging from the cave, he sees above them a giant and ornately built white city sitting on stilts above the tops of the trees. He wakes the others to show them. It is quite beautiful. They realize they must get up to it somehow.

However, the Daleks have found the cave. They are trapped. With nothing else for it, the Doctor goes outside and tries to pose as the robot. But they know the robot has been destroyed, and nearly exterminate the Doctor as he flees back inside the cave. He begins to activate his machine. They will have to use it here and hope that they are not destroyed in the process.

The door closes and the lift ascends. The Doctor tries to communicate with the robot, but it does not respond.

The Daleks advance on the cave and find no one inside. A scan of the walls reveals the existence of the lift. A Dalek is despatched back to the time machine to retrieve an electro unit.

The lift arrives at the top, opening into the city. It is just as impressive inside. The robot beckons the time travellers to follow it. At the junction of two corridors, the robot meets another of its kind. They communicate with each other mechanically. The first robot then shows them a door and they are invited to enter. Once inside, the door closes behind them.

Inside, the room is virtually featureless, with a bank of windows opening onto the corridor on one side. A bed sits against the another wall. However, in the centre of the room and leading upward is an extraordinary structure made of wood, rope, and cable. It consists of stairways and ladders all roughly built. From the top of it, a disheveled man leaps down.

After a shaky start, the lines of communication open. The travellers find out that he is Steven Taylor, an astronaut from Earth who crashlanded on Mechanus something like 2 years ago. He has been trapped here with the robots - Mechanoids - since then. He tells them that the Mechanoids were sent here 50 years ago to clear the area and prepare a landing and living area for the first colonists from Earth. But, because of an interstellar war, the colonists never came. The robots have been waiting ever since. As neither Steven nor the TARDIS crew know the robots' code, they are kept as prisoners... and as zoo specimens. Hence the viewing windows.

Meanwhile, the Daleks' electro unit has arrived. They use it to open the shaft and activate the lift. Information from Skaro has told them about the "Mechon" robots. There will be a fight, and the Daleks may not win. They press forward anyway.

Ian and the others are galvanized into action to try and escape, despite Steven's pessimism. The wooden stair and ladder construction attracts Ian's attention. It leads up to the roof, which is unfortunately 1500 feet about the planet's surface. The Mechanoids have figured it is escape proof and so allow Steven to go up unhindered. And it has worked so far.

The Doctor and Ian got up to the roof with Steven. Initially, it is clear why the Mechanoids are so confident. It seems escape-proof. However, Ian spots a spool of cable which is used as an aerial. Once he finds it can be detached at its junction box, he believes it can be used to lower them to the ground.

Going inside, Ian announces his plan to the others. Steven had thought of it before, but obviously couldn't manage it by himself. Despite their misgivings, all agree it is worth a try. This is further galvanized when they see through the observation window that 2 Daleks have arrived, looking for them.

The Doctor activates his machine before retreating to the roof with the others. The Daleks force their way into the cell and quickly realize the travellers are on the roof. But 1 Dalek is destroyed by the Doctor's machine and the other by a Mechanoid before they can sound an alarm.

Ian pulls the cable free, afraid he has caused some damage to the system. But they must concentrate on their escape. Vicki looks over the edge to the ground and is paralyzed by a fear of heights. She must be blindfolded and lowered from the roof.

As they work, they do not see the smoke beginning to billow up from the cell area. Whether from Ian's damage, the Doctor's machine, or the Daleks' guns, a serious fire has broken out below them. Steven is the first to notice, immediately letting go of the cable in order to return to the cell. He is searching for his mascot, a stuffed panda bear called Hi-Fi!

Vicki is nearly dropped at this abrupt change in manpower. The others struggle to hold her and to keep themselves from falling over the edge themselves. They barely succeed. Steven has disappeared into the thickening smoke.

Inside the city, a full-scale battle has broken out between the Daleks and Mechanoids. Each side inflicts heavy damage on the other and soon the conflagration grows larger. The entire city is on fire.

Steven manages to retrieve Hi-Fi and to avoid a Dalek. He begins to climb upward again.

Vicki, Barbara, the Doctor, and Ian make it to the jungle floor. They try to wait for Steven, but the cable has caught fire and the city has begun to collapse. They must retreat to safety.

Later, Ian emerges from the Dalek time machine, having found it deserted. All of the Daleks have been destroyed. Curious about the accuracy of the machine, the Doctor goes inside to investigate. Ian and Barbara realize that they can use it to get home. They ask the Doctor's help and he reacts with anger. He feels it would be suicide to even try to operate an alien time ship and forbids it.

Meanwhile, Steven has managed to escape the destruction of the city. He wanders the jungle, calling for the others and trying to avoid the fungoids.

Ian and Barbara plead with the Doctor to help, but he is adamant and an argument blazes. Vicki also tries to reason with him, making sure he knows that she will still be with him even if they go. Reluctantly, he agrees to show them how to operate it, giving them only a 50% chance of success.

But the risk pays off. Ian and Barbara arrive inside a garage in London, December, 1965. They are 2 years out, but very glad to be home. As instructed, they activate an auto-destruct mechanism and destroy the alien craft. Overjoyed to be home again, they take time to enjoy the city. They say their goodbyes to the Doctor into the air, try to return to a normal life.

The Doctor and Vicki watch their farewells on the Time/Space Visualizer. Vicki is happy for them, but the Doctor is devastated by the loss. It is time they were off. The TARDIS dematerializes from Mechanus.