Dylan receives a confidential communication from a friend of his, Marshall Man-ka-lupe, who is a prominent Commonwealth politician. The security on the communication is so high that even Rommie cannot listen in.

Man-ka-lupe says that he has learned that a notorious assassin, "The Leper", is going to attempt to assassinate him at a public appearance on Lundmark in three days. He asks for Dylan's assistance to prevent this, but warns him not to tell his crew any more than he absolutely has to, because if The Leper finds out that they are on his tail, it may make it more difficult to catch him.

Dylan takes Beka and Tyr (who are bothered by the lack of detail he is able to provide them) to Cassius Drift on the Maru. They make contact with the criminal underworld, claiming that they are working with The Leper, and looking to hire people to help him out. Dylan eventually offers the job to a woman. She immediately attacks him, but he overpowers her. He informs Beka and Tyr that this woman is The Leper's sister.

Back on the Maru, Beka and Tyr object to Dylan bringing The Leper's sister aboard. The woman, Sascha, claims that she thought they worked for her brother, and wanted to kill them to send him a message, since she hates her brother. She tells Dylan that, when they were young, she and her brother came home to find their parents and older sister dead. They traveled around, leading a life of crime, until she discovered that their family had been killed by her brother, who had been hired by one of her father's enemies. She tells Dylan that The Leper improvises his assassinations on-site, and that he has a custom-made gauss gun, designed for easy concealment.

The final jump to Lundmark proves to be a difficult one, and on emerging from slipstream, the Maru is attacked by several ships. Beka quickly takes them back out of the system, but they do not know another way in. Sascha says that she does – or knows someone who does. She knows a smuggler named Crescent who navigates the back routes in and out of Lundmark for a living. She offers to take them to him.

Sascha guides them to a drift, which has been converted from the wreck of an old High Guard ship. It is a "private prison", run by a mobster named Gunyan. Crescent is a prisoner, and they will need to break him out.

Dylan and Sascha pose as a married couple, with Sascha pretending to be Crescent's niece, coming to visit him on his 50th birthday. Dylan disguises some explosives as a set of holo-novels. As they are preparing, Sascha kisses Dylan. Dylan is suspicious of her, but she protests that she is not "playing" him, she is here for revenge on her brother.

While Dylan and Sascha go onto the Drift, Beka and Tyr wait nervously on the Maru.

Dylan and Sascha are getting a close look from the Drift guards, but eventually talk their way in to see Crescent. When Dylan mentions Crescent's 50th birthday, Crescent tells him that the guards had just asked him how old he was – obviously double-checking their story – and he had told them that he would turn 57 in six months. The guards slam the cell doors shut.

Dylan uses the explosives to blow open the door, takes guns from the fallen guards, and engages in a firefight until he, Sascha, and Crescent are trapped in the corridor by sliding doors. Gunyan appears in a hologram, and threatens to kill Dylan unless he does a favour for him and kills two intruders he has captured – Beka and Tyr. With eye contact, Dylan gets Beka and Tyr to duck so he can shoot the guards, but Gunyan once again traps them in the corridor.

Gunyan tells Dylan that he does not like killing people, but he needs to be feared, and killing people is the best way to achieve this. Dylan offers him an alternative – since they are going to kill The Leper, and cannot take credit for it, Dylan offers to let Gunyan take credit for killing The Leper. Gunyan agrees.

Crescent guides Beka along the back route to Lundmark, which requires them to travel through a nebula called "Dragon's Breath". It is a treacherous route, but they do not have time to go around.

Dylan is comparing notes with Sascha, who seems to be trying to seduce him. Dylan notes that Sascha seems to know more details about Lundmark than he would expect. She reveals that she was the one that leaked the information to Commonwealth Intelligence, and admits to having been in contact with her brother, although she says that she is not working with him. She observes that they are using each other to get to The Leper.

Beka gets through the nebula, but in the process, she discovers that Crescent has only been through it once before, not "making a living" at it like Sascha said. Tyr forces a confession out of Crescent – he made the one trip for The Leper, and that is how Sascha found out about him, but he insists that she really does hate her brother.

When the Maru lands on Lundmark, Dylan presents them with a new plan: Sascha and Crescent will stay on the Maru. They accept this without objection. As they leave the Maru, Dylan reveals to Beka that he suspects that Sascha is The Leper. He expects that she will not stay on the Maru.

Sascha and Crescent do leave the Maru, and Dylan, Beka and Tyr follow them, although Dylan is still allowing for the possibility that he is wrong. Tyr scouts out the area for possible vantage points for an assassin.

While Dylan is watching Sascha, she assembles her jewelry into a gun.

Sascha and Crescent split. Dylan stays with Sascha, while Tyr and Beka follow Crescent. They catch him, but before they can get any answers, Crescent is shot by an unseen attacker.

Dylan confronts Sascha, saying he lost Beka and Tyr, and asking her to help him out. She doesn't believe him, and attacks him. They fight, and she ends up holding Dylan at gunpoint. At this point, Beka calls to Dylan on the communications device. Dylan tells Beka to "take her out", and Sascha runs for cover.

Dylan tracks Sascha down, and finds her aiming a gun at Man-ka-lupe (who is in the middle of a speech). He shocks her unconscious with his forcelance, and takes her into custody. Sascha claims that the reason Dylan could catch her is because he is not afraid of death, but Dylan counters that what she saw was faith, and belief in doing the right thing.

As Dylan is returning to the Andromeda in the Maru, Man-ka-lupe contacts him, thanking him for saving him, and offering him a place in his administration, which Dylan declines. Tyr interrupts, telling Dylan that Sascha has escaped from prison, apparently with help. Dylan speculates that that help came from her brother.