The crew of the Andromeda are testing out the new systems from their retrofit, and the systems are performing well. They emerge from slipstream near a ringed planet with a moon, Septa Parisis.

Andromeda detects the launch of a small attack drone from the moon. It withstands a shot from the Andromeda, and hits the ship with something that starts to drain its power. A gravity field generator from the moon also starts to affect the ship, and their orbit starts degrading. Andromeda says that she can hold them in orbit for a while, but they will soon crash into the moon.

The moon is littered with wreckage from other ships. Harper also locates a point-singularity weapon, similar to the ones on the Magog Worldship, although Andromeda says that it is not currently operational.

Although Andromeda is able to locate both the Gravity Field Generator (on the surface) and the source of the power drain (deep underground), her power problems prevent her from attacking them directly. Dylan decides to take the Maru to the surface of the moon in order to destroy them.

Beka and Harper recall legends of Septa Parisis, that there are vast treasures on its surface. They plan to retrieve some of this treasure after saving the Andromeda.

Dylan receives an AI message from one of the Triumvirs, Tri-Lorn. He orders Dylan to destroy Septa Parisis. Dylan insists that they need as much intelligence as they can gather first. Tri-Lorn tells him that the moon was created by Kroton, "The Great Engineer", who is half-human, half-android. Kroton is rumoured to be the designer of the Magog Worldship, and the source of many other technical problems (such as an entire planet's androids going berserk) over the past 400 years.

Beka and Harper discuss what they will do with their wealth from the treasure, but Dylan reminds them that the primary purpose of the mission is to save Andromeda. He does allow that they can collect some treasure afterwards, if there is time and opportunity.

Trance warns Dylan that what his is looking for is also looking for him.

Dylan, Beka, Harper, and Rommie take the Maru to the moon's surface. On the way down, they pick up a distress signal, from a Commonwealth ship, so they land near its source. As they start to explore the area, someone starts shooting at them. Dylan sends Rommie at the shooter from the front, and she absorbs several shots as Dylan circles around behind the shooter's position. He confronts the shooter: Molly.

Molly tells Dylan that three of the seven crew members on her ship survived their crash on the moon, but the other two have died in the meantime, and she feels responsible. She explains that the objective of their mission was the point singularity weapon – to study and destroy it. She also tells them that she has been attacked frequently, by one man, but he sometimes seems to be everywhere at once.

Suddenly, the crew is attacked by a group of androids and a single human (whom Molly identifies as her attacker). They retreat to the Maru, but the Maru is now trapped by the power drain.

Harper explains that he made some modifications to the Maru during the recent retrofit, but he needs some extra power. Rommie volunteers to tap the Maru into her internal power plant, and Harper activates his modifications. The cockpit section of the Maru seals itself off, and separates from the rest of the ship into a small shuttle-like vehicle.

Molly sets up some radio-controlled explosives, for use against the gravity field generator and the power drain device. She tells Dylan that she (as a Lieutenant) acknowleges the chain of command, but also takes him to task for not keeping in touch with her after their last experience with the Ogami.

Dylan takes Molly with him to attack the gravity field generator on the surface, and sends the rest to take out the power drain device under the surface.

Rommie identifies a wrecked transport ship on the surface, which was known to be carrying high-tech computer chips, which are not readily available since the Fall of the Commonwealth.

Dylan and Molly are attacked by Kroton and several "clones" of him. Kroton sets off an explosive, and Dylan and Molly fall into a cave complex, but he pursues. They hear lots of footsteps approaching, and turn to run, but Molly wonders if it might be a trick. Dylan turns back to look, and is shot at, so they run, until they are pinned down by a defense system.

Harper, Beka, and Rommie lose contact with Dylan, Molly, and the Andromeda, but they use a laser mounted on the Maru-shuttle to dig into the surface of the moon. Rommie's power is quickly fading, and Harper is worried, but they manage to cut through to a large, open area. They launch a flare, and see a large structure, which appears similar to the Magog Worldship.

Dylan and Molly use parts scrounged from the wrecked ships and Dylan's forcelance to devise an explosive device in order to take out the defense systems. They move further into the cave complex, and find an army of androids standing in readiness. They realize that the power being drained is being used to power up these androids. Dylan asks Molly for ideas. She scrounges more parts and creates another explosive, which they use to set off a chain reaction among the androids, and destroy them. They then head for their primary target.

Beka and Harper get their bomb placed, and head back for the surface, with time to spare (and collect the computer chips).

As Dylan and Molly are setting their bomb, Kroton attacks them, with a few of his "copies". He threatens to lead an android revolt, and, between this and the Magog, the Commonwealth will fall. Kroton has Dylan pinned down, but Molly shoots him in the back, and he falls. They set the bomb and leave.

Lying on the floor, a red glow shines in Kroton's eyes. He sounds like he is receiving orders, and says that it is "time for the Primary Event".

As Dylan and Molly are fighting their way out, Trance contacts them from the Andromeda. She says that the moon is shaking to pieces, and they have to get out now. They manage to fight their way to the shuttle and launch. Dylan tells Trance to activate the bombs, which destroy both devices. The shuttle re-joins with the Maru, and they return to the Andromeda.

Suddenly, the moon splits in half, revealing the Worldship-like structure inside. This structure is a ship, and Kroton is attempting to escape with it. Dylan tells Rommie to open five slipstream portals in the area. Only one will be "real", and the disruption will be too much for another portal to be opened by Kroton. Kroton chooses the wrong portal, and the ship explodes, but an escape capsule manages to get away through the real portal.

Harper examines the chips, and discovers that they have all been rendered useless by prolonged exposure to radiation.

Dylan offers Molly a spot on Andromeda's crew, but she turns him down, telling him that she wants her own life and career.