Deep within a ragtag space fleet called the Clutch, a Galyari nursemaid tries to settle down her young charges by telling them of the Sandman, the legendary bogeyman who tears the skins off misbehaving children... but this is no mere bedtime story. Her cry for help is cut off in mid-transmission, and the Galyari’s trade director, Nrosha, rushes to the nursery in response, instinctively knowing that something terrible is happening to her children. Orchestrator Shol sends a security patrol led by Commander Brel, but they are also too late, and despite Brel’s attempts to bar her way, Nrosha pushes past and sees the unspeakable thing that has been done to her children. Like Shol’s predecessor, they have become victims of the Sandman... who is also known as “the Doctor.”

Nearly two years later, the TARDIS materialises aboard a dingy ship owned by the star gypsy Mordecan. He is initially suspicious of the Doctor and Evelyn, but Evelyn manages to convince him that they simply missed their target. Mordecan has an appointment on the Clutch, with a rather nervous business partner named Nintaru, and he’s waiting for the Galyari to transmit an approach vector before he can dock. The Doctor -- who doesn’t seem to be looking forward to his own “appointment” -- asks Mordecan to show his friend the Clutch, and Evelyn marvels at the sight. The Clutch is a multicoloured fleet of ships like a giant school of fish, clustered together for mutual protection. The Galyari are at the heart of the Clutch, and the Doctor compares the hundreds of species which tag along with them to parasites living off an elephant; he meant symbiotes, but his choice of metaphor nonetheless irritates Mordecan.

The Sandman still lurks in the shadows on the Clutch, preying on the weak and elderly. There is nothing Shol can do against this beast, but all other criminals on the Clutch will face the harshest penalties of the law as Shol and Brel take out their frustrations at being unable to fight their real enemy. Shol turns control of Traffic over to the sub-Orchestrator, and visits Nrosha to ensure that she carries out her duties properly. Since her family tragedy, her work for the Clutch has suffered, and Shol fears that her hatred of the Sandman will cloud her mind and blind her to any illegal activity on Mordecan’s part. Indeed, Nrosha fully believes that Galyari security patrols should concentrate on killing the Sandman rather than the day-to-day policing of the Clutch; in a way, she respects the ruthless Sandman more than she respects the cowardly Shol. Nevertheless, she promises to observe Mordecan and do her duty -- even if her orders come from a “leader” who has done nothing to stop a monster that tore the skins off her children...

Mordecan’s ship docks with the Clutch, becoming just one more of the interconnected ships that form the fleet. He’ll be here for three days, and then he’ll be leaving again, whether the Doctor has collected his weird blue box or not. Mordecan advises Evelyn to avoid the Warrens, the most dangerous area of the Clutch -- and to dump the Doctor at her first opportunity. As the Doctor and Evelyn set off, Mordecan contacts his partner Nintaru and runs the extremely nervous alien through their itinerary. After Mordecan’s meeting with Nrosha, he and Nintaru will meet their other contact in the same ship as before -- as soon as they find out where that ship is in the ever-changing Clutch. Nintaru remains extremely nervous; the Galyari zealously enforce their trade laws. But this is the last shipment of Nintaru’s “merchandise”, and as long as he keeps his head this will all soon be over...

Evelyn notices odd behaviour from the Galyari security patrols as she and the Doctor stroll through the Clutch. The Galyari have independently mobile eyes, like those of a chameleon, and extremely precise vision -- yet none of the patrols seem to give them a second glance. Evelyn has guessed that the Doctor materialised outside the Clutch deliberately to give her a look at the big picture first, and she’s also guessed that this is not going to be a casual visit. She is proven right when the Doctor breaks into the Orchestrator’s chambers, deliberately tripping an alarm on his way in so he won’t have long to wait. There are no guards; Galyari cannot comprehend the workings of the criminal mind, which is why they crack down so harshly on the criminals they do catch.

Evelyn is shocked by the Doctor’s brutal and unexpected behaviour, but he doesn’t seem to care. He’s here to make sure that the Galyari cease trading in weapons; every few generations, they seem to return to their old ways, and the Sandman always returns to stop them. Shol knows that the end of the arms trade could impoverish his people -- but he also knows he has no choice but to obey...

Elsewhere, Mordecan and Nrosha discuss the business of trade. Mordecan has brought a shipment of sunbirds from a world which considers them holy; less spiritual factions were willing to part with a flock of over 100. Nrosha is pleased with Mordecan’s offer and offers him a rich commission, but Mordecan realises that she’s more deeply troubled than usual. He considers her a friend of sorts, and sympathises for her loss, but still she refuses to discuss the doom that stalks the Galyari; their relationship with the Doctor is a private matter. Or so she thinks until Mordecan recognises the name and reveals that a man calling himself “Doctor” materialised aboard Mordecan’s ship earlier that day. Suddenly Nrosha becomes very interested indeed in what Mordecan has to tell her.

Evelyn remains bewildered by the Doctor’s behaviour, and he thus orders Shol to tell the story of the Sandman. Shol thus relates the horror that befell his people, of the time that their homeworld was overrun by burrowing vermin that slaughtered the populations of whole cities. The great hero General Voshkar led a campaign against the enemy, but was defeated in the final battle when the beasts tunnelled beneath his troops, catching them off guard. The Galyari’s heavy weaponry could not be brought to bear in such close quarters, and Voshkar’s troops were slaughtered. Worse, a fiend calling himself the Doctor, or the Sandman, appeared from out of the mists, ordering Voshkar to retreat or suffer the consequences -- and to reinforce his threat, he took as trophies the skins of those fallen in battle.

Horrified by what he had seen, Voshkar addressed the Council of Directors, assuring them that the burrowing animals were mere vermin and that the real enemy was the monster calling himself the Sandman. The Directorate sent Voshkar back to Galyar with a force of 20,000 soldiers, and this time, the troops used land mines to flood the vermin’s tunnels with molten lava. Voshkar then led his troops to reclaim the fallen cities and the Srushkubr, the “memory egg” at the heart of every Galyari world. But the Sandman was waiting there, wearing a coat woven from the skins of their dead, and the Galyari found that the mere sight of him caused agony. The fiend told Voshkar that he had given the animal Cuscaru the gift of intelligence in order to stand them in the path of the Galyari -- and that from this day forth, the Galyari would never live on a world’s surface again. So speaking, the Sandman shattered the Srushkubr into fragments, planting his curse on the Galyari forever.

Evelyn doesn’t understand this part of the story, and the Doctor explains that the Srushkubr is like an organic data bank, a physical embodiment of race memory with which every Galyari shares a deep, intuitive connection. Every colony established during their migration has a Srushkubr at its heart, and despite Shol’s protests, the Doctor claims that the world they are speaking of was just one more colony like all the others. But that’s the only part of the story he denies. He has indeed cursed the Galyari, to prevent them from cursing others...

Mordecan tells Nrosha all he knows about the strange Doctor, and once he’s finished, Nrosha ushers him out and contacts Brel, claiming to have vital information. Brel is on his way to investigate further mysterious deaths, but Nrosha tells him they have an opportunity to end all the horror now. If Mordecan is telling the truth, then the Sandman travels in a craft of his own. It may be a strange and unconventional vehicle, but the implication remains that the Sandman’s supernatural powers are the stuff of legend, and that he is as mortal as any Galyari. Though it’s said that even to look upon the Sandman is death, Brel does not need to be precise in his aim; the Clutch is currently being controlled from the auxiliary command deck, and any damage Brel inflicts if he opens fire in Shol’s office will be merely a minor inconvenience. Brel considers briefly, and then agrees to take the risk. If all goes well, he will go down in history as the hero who killed the Sandman...

Meanwhile, his business with Nrosha concluded, Mordecan concentrates on more illicit matters. Most of the access terminals in the Clutch are monitored, but those in the warrens are usually in a poor state of repair and are ignored -- which is why Mordecan repaired one on his last visit. He uses this unmonitored terminal to transfer a current map of the Clutch to Nintaru, and then kicks back at the bar to relax while Nintaru makes his way to the rendezvous point.

Evelyn is disgusted by the apparent glee which the Doctor takes in Shol’s fear. Shol agrees to speak to his trade director, but begs the Doctor to put an end to the unnatural deaths which have recently plagued his people. The Doctor, taken somewhat aback by this request, requests that Shol refresh his memory about said deaths. Though reluctant to relive the horrors, Shol explains that the first to go was his predecessor, taken in his sleep after a meeting arranged by Mordecan. Apparently one of the gypsy’s contacts wished to sell something to the previous Orchestrator, but following the Orchestrator’s death, nothing came of those plans. Since that first death, there have been countless others. At first, the Sandman would only harvest the skins which the Galyari shed naturally during their “growth sickness” -- but soon, he began to harvest the skins before they were shed.

The Doctor and Evelyn prudently retreat, and the Doctor destroys the lock on his way out to delay pursuit. Unfortunately, running away has put a substantial dent in his reputation as a fearsome monster -- a reputation he still claims is based largely on fact. As he and Evelyn flee through the Clutch, the Doctor notices the lights flickering and realises that a disguised Galyari surveillance drone must be tapping into this ship’s incompatible power source. He locates the drone and tries to rewire it to help him find Mordecan, but is interrupted by an announcement: this ship is about to leave the Clutch, and all adjacent ships will temporarily detach from the Clutch to make way for it. The Doctor tries to finish his work on the run, but doing so slows him down -- and Evelyn, running on ahead, ends up stuck on a different ship when the airlocks are sealed between them.

The Sandman’s flight has proven to Nrosha that he fears death, and that he therefore can be killed. Shol still fears the reprisals should they try and fail, and points out that their drones don’t have enough data to track the legendary being. Nrosha advises sending out patrols in force, with orders simply to track the Doctor but not to detain or oppose him; Brel will be the one to hunt him down and fire the killing shot. Shol reluctantly authorises this mission, and once the engineers have repaired the door, Brel sets off to prepare. Shol seals the door behind him, even though this didn’t stop the Sandman before, and warns the contemptuous Nrosha that if Brel fails, Shol will have him killed to buy back the Sandman’s favour. Meanwhile, Brel dons his battle dress and prepares himself mentally for the greatest moment of his life.

The extra patrols have Nintaru severely rattled; though the Galyari don’t appear to be hunting him specifically, he’ll still be in serious trouble if he runs into them. He thus contacts Mordecan to warn him of the danger, and changes his route to avoid populated ships. Mordecan sets off to keep their rendezvous, but bumps into Evelyn, who correctly guessed that he would be in the warrens he’d mentioned earlier. She plays on his “rugged nobility” and assures him that she has no interest in his current illicit activity, just in his meeting with the previous Orchestrator. That was two years ago, ancient history as far as Mordecan’s concerned, and he tells her that all he did was introduce Nintaru to the Orchestrator, who refused to deal for whatever it was Nintaru had on offer. Mordecan doesn’t know what it was -- he asks no more questions than necessary -- but he does know it was something unusual...

The Doctor’s captive surveillance drone has picked up the conversation between Nintaru and Mordecan, and once the Doctor’s ship docks with the Clutch again, he tracks Nintaru down to question him further. Nintaru is passing through one of the Galyari’s many aviaries, but is under attack by the birds, which have sensed his timidity. The Doctor helps to drive them off, explaining to the shaken Nintaru that the Galyari, despite their chameleon-like appearance, are descended from an avian species and venerate birds as their early ancestors. He then questions Nintaru, recognising his species, and is disturbed to learn that the Clutch is very close to Nintaru’s homeworld -- a world which was once called Galyar...

Every world that the Galyari colonise, they rename Galyar, to assert their territorial right to the planet. Over the millennia, as the legend of the Sandman grew in the telling, they came to believe he had driven them away from their true homeworld. But the planet is now inhabited by the Cuscaru, Nintaru’s people, and they have legends of their own. When their astronomers spotted the Clutch in deep space, and identified it, world-wide panic ensued. Careful research and investigation led them to discover trace elements of an alien artefact in their planet’s soil, presumably the artefact which was destroyed in the final battle for their world. Nintaru originally came on a peace mission, to return the Galyari’s lost relic, but it has since become a matter of trade. The Doctor is horrified by the implications of Nintaru’s story. When he shattered the Srushkubr, he released a blast of neural energy which permeated the living cells of all Galyari present at the final battle. If the ashes of the broken Srushkubr are reunited with those energies, the consequences could be disastrous... and may already have been.

Shol and Nrosha wait for word from Brel, but the waiting grows too difficult for Shol, who decides to resume his ordinary duties to keep himself occupied. However, when he tries to contact sub-Orchestrator Korshal in auxiliary command, he receives no answer. It appears that the Sandman has struck again, but according to the security patrols, the Doctor is nowhere near auxiliary command and he can have no idea that Brel is hunting him down...

Brel arrives to kill the Doctor, but freezes into immobility at the sight of the real monster. Mordecan seizes Brel’s gun and kills the thing, which is revealed to be a hollow Galyari skin. Though shaken by what he’s seen, Brel still intends to kill the Doctor, until the Doctor shows him the truth by removing his multi-coloured coat and waistcoat. The Galyari were once able to camouflage themselves, like chameleons, and though this ability has been lost over time, they still retain the sharp eyesight that once enabled them to distinguish fellow Galyari from their surroundings. Unfortunately for them, this renders them vulnerable to intense migraines when exposed to intense clashing colour combinations. Brel realises that the Doctor has willingly confessed that there’s nothing supernatural to his powers, and must conclude that the walking skin represents something extraordinary which the Doctor may be able to explain. Brel agrees to summon a medical team for Nintaru, but before he can do so someone addresses the Clutch from auxiliary command -- in a voice which the Doctor finds disturbingly familiar. This is the real enemy, the new Sandman, and the Clutch’s new Orchestrator. Soon all the Galyari will serve him, but he will allow the Clutch’s alien inhabitants to depart in peace, on condition that they bring him the Doctor.

The real enemy revealed, the Doctor insists that Brel patch him through to Shol. Brel does so and transmits an image of the husk monster as well. The Doctor reveals that fragments of the Srushkubr have been brought to the Clutch, and when Shol admits that the previous Orchestrator was a direct descendent of General Voshkar, the Doctor’s suspicions are confirmed. There is a demon in the Clutch, and in order to get rid of it, the Doctor requires access to the sacred cultivation chambers. Nrosha insists that this is a trick, but Shol realises that the Doctor could easily use the blue box Mordecan described to get into the chambers without help, and decides to hear the Doctor out. Enraged, Nrosha takes a security patrol to auxiliary command, intending to prove to Shol that he’s made a pact with the devil.

Once he’s sure Nintaru will recover, the Doctor takes Evelyn, Mordecan and Brel to the aviary to collect feathers for the cultivation chamber. On the way, he explains that while the facts of the legend are largely true, the emphasis is quite different. The world Shol called Galyar was a colony seeded by a Srushkubr, and that the Cuscaru were the true natives of that world, who were just evolving into an intelligent civilisation when the Galyari arrived. The Doctor provided the Cuscaru with advice on organising their resistance, and thus gained access to the Srushkubr; at first he didn’t understand what it was, but eventually worked out that in order to interface with it he would require dead Galyari tissue. Sadly, there was much to be found on the battlefield...

When he was found harvesting skins from the dead soldiers, the Doctor played the part of a monster, trying to frighten Voshkar into leaving peacefully. Voshkar refused to do so, but by the time he returned, the Doctor had learned how to manipulate the Srushkubr, and through it, the race unconscious of the Galyari. Voshkar’s contempt for the Cuscaru was his undoing; since he would not accept that these “animals” had prior claim to this world, the Doctor smashed the Srushkubr, releasing a blast of neural energy which imprinted upon the Galyari a subconscious terror of the Sandman that has lasted for millennia. However, as a side effect of the blast, Voshkar and his men were irradiated with neural energy, and that potential has been passed down through generations. When Nintaru presented fragments of the Srushkubr to Voshkar’s direct descendent, the latent energies were released, and a new Srushkubr was created -- a malevolent embodiment of legend formed around a living core, which has been “harvesting” skins and adding them to itself ever since. The husks are now walking embodiments of Galyari race memory, and Brel could no more shoot one than he could turn the gun on himself.

However, this ability to control the Galyari’s collective unconscious will allow the Doctor to defeat the Sandman. Using feathers from the aviary, some stored Galyari skin cells, and some of the Doctor’s own blood, the Doctor uses the cultivation chambers to grow a Srushkubr of his own. He then sends Evelyn and Shol back to the command deck, and advises Brel to contact all other Galyari in the Clutch and have them seal themselves away behind impregnable bulkheads. The Doctor and Mordecan will go to the auxiliary command deck, confront the Sandman and switch control of Traffic back to main command. Brel would prefer to be out in the corridors fighting the husk army which is roaming throughout the Clutch, but Evelyn guesses that the Doctor is about to unleash something that will affect all Galyari not safely locked away. Shol realises that this is true; the being he’d thought of as the embodiment of all evil is trying to protect innocent Galyari while he turns himself over to the real enemy.

The Doctor and Mordecan find the corridor outside auxiliary control littered with bodies -- and dead husks. Though the security guards accompanying Nrosha froze at the sight of the monsters, Nrosha’s hatred of the Sandman was so strong that she actually fought her way past them. When the Doctor and Mordecan confront the Sandman, they find that he has torn her apart -- but the fact that she was able to fight him at all proves the depth of her hatred, and of her love for her children. The Sandman jeers triumphantly at the Doctor, who recognises his voice as that of General Voshkar; his will was stronger than all the other latent minds in the Galyari race memory, and he has been reborn in this new form, apparently stronger than ever. Not only does he have the ability to control the skins he has taken, they have regained their ability to camouflage themselves, another reason why the Galyari on the Clutch were never able to find their enemies. Now Voshkar will lead his army back to the Cuscaru’s world, destroy them, and reclaim it in the name of Galyar.

The Doctor is furious. His Sandman was a legend, not a killer; all he ever did was remove a few shed skins from the nurseries and plant fear in the Galyari subconscious to prevent them from being a threat to others. But Voshkar will turn the Clutch from an interstellar flea market into a battle fleet that will wreak havoc throughout the galaxy, and it’s up to the Doctor to stop him. Enraged, Voshkar attacks the Doctor, and as they battle, Mordecan slips past them and transfers control of Traffic through to Shol. Following the Doctor’s earlier instructions, Shol opens all internal bulkheads except for those behind which the Galyari are sheltering. Within moments, all of the birds in the Clutch are flocking through the corridors, attacking the husks wherever they are found. Voshkar begins to convulse in pain as he loses his husks, and the Doctor and Mordecan retreat as the birds fly in and attack Voshkar himself. Through the new Srushkubr, the Doctor has created a psychic bond with the birds, creatures which even Voshkar couldn’t bring himself to harm. Soon the Sandman has been vanquished.