The Doctor and his shape-shifting companion Frobisher attend the premiere of "Star Wars" at Mann's Chinese Theatre in 1977, but as they leave, two assassins -- a S'Raph Tzun named Sha'ol and his partner, the Veltrochni Karthakh -- materialize aboard the TARDIS and attempt to kill the Doctor. Their time-travelling technology has left them in an incompatible time phase, however, and the Doctor is able to eject them from the TARDIS. Determined to find out where they got their equipment and who wants him dead, the Doctor follows their path through Time to the planet Vandor Prime in the Gamma Delphinus system.

There, he is reunited with Sabalom Glitz and his partner Dibber, who have just stolen a ship called the Nosferatu in order to recover the proceeds of one of their previous robberies. Unfortunately, the head of Vandorian security and intelligence, Niccolo Mandell, is waiting for them at their hideout, but instead of simply arresting them he offers them a deal. A decade ago, Glitz fenced a stolen Veltrochni relic which Mandell bought through intermediaries on behalf of the Vandorian government; now the Veltrochni have learned that the Vandorians have it and are demanding its return. In order to avoid a public scandal, Mandell orders Glitz to reassemble his team and steal the relic back from its current safe house, the Thor Orbital Facility. Failure will mean a Veltrochni invasion and the deaths of millions in an interplanetary war. Uncertain what to do with the Doctor, Mandell impounds his TARDIS and orders him to help Glitz, and agrees to investigate the mystery of the time-travelling assassins while the Doctor is otherwise occupied.

The Doctor, Frobisher, Glitz and Dibber set off to reassemble the old team, but they attract the attention of Mandell's policewoman wife Kala, who is unaware of her husband's involvement in the case. The Doctor successfully talks Monty Kast and the brother-and-sister team Liang and Chat into reuniting for one last heist, but then hits a snag when it turns out the old teammate Oskar, master of disguise, was killed some years ago due to a case of mistaken identity. There remains only one man left from the team, their former leader Jack Chance -- but Chance is now the semi-legitimate owner of the Cafe Terrestrial and he isn't interested in risking his position even to prevent a war. Kala learns that the old team has reassembled and has a Tac team raid the Cafe to bring them in for questioning. Chance is forced to flee and joins up with the team after all, and in order to avoid disciplinary action, Kala must bring him in and prove that her hunch was right.

An Ogron raiding party arrives in the star system and begins attacking isolated Vandorian ships, and the Vandorians suspect the Veltrochni of the attacks. When a Veltrochni Dragon responds too late to a Vandorian ship's distress call, a Vandorian corvette encounters it and accuses it of attacking the Vandorian ship, and the result is an exchange of fire that results in the destruction of the corvette. Political turmoil increases. Meanwhile, Sha'ol and Karthakh attack the facility where the TARDIS is being kept, and steal it in order to force the Doctor to come to them. Mandell views the security records and recognizes the famous bounty hunters, and contacts them, offering them a bonus if they agree to hold off on their contract until the Doctor has finished his mission for Mandell. Sha'ol and Karthakh consider for a moment and then agree.

Glitz's team learns that temporal scientist Professor Hoffman has been invited to the Thor Facility to look over the temporal baffles which keep the asteroid phased one hour ahead of real time. They kidnap the real Hoffman and the Doctor takes his place, smuggling Frobisher into the facility in order to scout out the place for their later assault. The Doctor learns that the temporal baffles were designed by Chronodyne Industries, which is based on the planet Dronid, and starts to develop some nasty suspicions.

While investigating a closed-off area of the Thor Facility the Doctor inadvertently exposes the activities of a rogue scientist, Cronan, who has been manufacturing drugs and selling them. Cronan flees and puts a huge reward on the Doctor's head, much to the disgust of his distributor, the mysterious Mr Zimmerman -- who is the same person who set Sha'ol and Karthakh on the Doctor's trail. Now, thanks to Cronan, every bounty hunter in the system is gunning for the Doctor and the result is chaos. The bounty hunters converge at the Cafe Terrestrial, which is destroyed in the crossfire as every hunter attempts to shoot down his, her, or its rivals in order to claim the reward for their own. In the confusion, Sha'ol and Karthakh arrive and kidnap Glitz and Frobisher, as additional hostages to force the Doctor to give himself up. As they depart their ship is attacked by the Ogron raiders, but Sha'ol and Karthakh convince the Ogrons to join forces with them and share the reward.

The Doctor decides reluctantly to complete his mission for Mandrell first, and heads back to the Thor Facility with a plan in mind. Liang uses a Veltrochni holo-suit to disguise himself as Mandrell, and claims that the Doctor, Chat and Monty are here to service the time dams. In fact, the Doctor reconfigures them, keeping a spare circuit for later use, and phases the Veltrochni relic back into real time -- and since the asteroid itself is an hour out of phase, the relic ends up in space where the asteroid was one hour ago, ready for the Nosferatu to collect. The team evades the guards and escapes, Liang more narrowly than the others, and sets off for the planet Elench to return the relic to the Veltrochni. First, however, they return the real Professor Hoffman to Vandor Prime, and he goes straight to the police -- specifically, to Kala Mandrell.

The Doctor and his team arrive on Elench, where Mandrell meets with the Veltrochni -- and double-crosses them, slaughtering them all. He intends to kill the criminals as well and frame them for the slaughter, and make it appear as if the relic was destroyed in the crossfire. The relic is in fact the last surviving Tzun data core from the Tzun homeworld S'Arl, and contains the secrets to building Tzun Stormblades; Mandrell and his associates will soon be rich beyond their wildest dreams. But then the Doctor informs him that thanks to Liang's disguise at Thor they've framed Mandrell as their co-conspirator. The Doctor needs to know more about Chronodyne Industries and the temporal baffles, but before Mandrell can tell him anything, the Ogron raiders attack and kidnap the Doctor and his gang -- and make off with the Core as well, to Mandrell's shock and fury. As the Ogrons depart, they are pursued by the Veltrochni ship which is still waiting for the landing party to report back, and Karthakh is forced to help the Ogrons destroy it to save their lives.

Frobisher escapes, morphs into the shape of an Ogron, and eavesdrops on a conversation between Sha'ol, Karthakh and their employer "Zimmerman" -- who looks forward to freeing himself of the Doctor's conscience, and on one occasion refers to him with the pronoun "we". Frobisher returns to the cells and gives the layout of the ship to the others, and the Doctor and Monty break into a ventilation shaft and make their way to auxiliary control. There, they open up the cell doors, releasing the others, and change the atmosphere of the ship to incapacitate the non-humans. Glitz and the others defeat the others in a gunfight, and Frobisher, disguised as an Ogron, captures Sha'ol and Karthakh.

The Doctor studies the bounty hunters' communicators and realizes that they are time rings, confirming his suspicions that "Zimmerman" is a Time Lord. Dronid, the homeworld of Chronodyne Industries, was once the home of a rival Time Lord faction; perhaps a Time Lord is selling Gallifreyan technology to other civilisations for his own purposes. Having learned of Glitz's and the Veltrochni's interest in the system and aware of their past acquaintanceship with the Doctor, "Zimmerman" must have sent Sha'ol and Karthakh after the Doctor as a pre-emptive strike to prevent him from learning about "Zimmerman"'s actions. But if so he's failed; the Doctor's experiences have all been broadcast directly into the Matrix, and the Time Lords of Gallifrey will know all about the incident by now.

The Doctor now intends to return the Core to Veltroch, but "Liang" now reveals himself to be the presumed-dead Oskar -- in fact a Whifferdill, like Frobisher, who infiltrated their gang on behalf of Mandell when the real Liang died during the raid on Thor Facility. Oskar tries to seize the Core, and during the fight which follows Dibber is shot and the Doctor is apparently electrocuted while pushing Oskar into a live cable. Sha'ol and Karthakh report the Doctor's death to "Zimmerman", who releases them from their contract and pays them -- and the Doctor revives moments later, having been placed in momentary stasis by the power surge through the temporal circuit he'd taken from Thor Facility.

The Veltrochni Ambassador, Brokhal, pieces together the clues and realizes that Mandell has been acting on his own without the authorisation of the Vandorian government. Kala is brought in for questioning and is horrified to learn that her husband has been associating with the criminals she's been hunting; Brokhal, convinced of her innocence, allows her to accompany the mission back to Veltroch to learn the truth for herself. Mandell, meanwhile, finds Cronan and sends him to kill the Doctor. Cronan reaches the Ogron ship and destroys it just as the gang is leaving in Sha'ol and Karthakh's ship; but Sha'ol is able to lure Cronan into a trap within a planetary orbit, and Cronan is shot down by one of his own torpedoes.

The Doctor and his associates travel to Veltroch, contact Brokhal and explain the truth. Mandell arrives as well and attempts to place the gang under arrest, but in his shock at seeing Kala waiting for him he slips up and reveals his guilt. Kala has no choice but to arrest him. The Doctor returns the Core to the Veltrochni, who have kept it as a reminder of the genocide they once committed. The Doctor asks that the gang be pardoned, and Brokhal agrees to do so, since they have prevented a major war. The Doctor and Frobisher depart as the survivors get back to their ordinary lives.