Rommie is on a secret mission to Machen Alpha, a planet neighbouring Mobius. Machen Alpha has a weapon called the Basilisk, capable of destroying planets, which they have already used once, and they are threatening to use it on Mobius. Dylan, Beka, and Trance are monitoring Rommie's progress from orbit in the Andromeda, and Harper, Tyr, and Rev are in the Maru, hidden in the ocean nearby, to provide her with transportation out.

Andromeda detectes that the Basilisk is moving out ahead of schedule, and moves to intercept it.

Rommie is meeting with Phillip Kim, one of Machen Alpha's top engineers. He is reluctant to give her any information until she gets him to safety. Rommie calls back to the Maru to report on her situation, and Tyr suggests that she take the information from Kim by force.

Security guards burst into the hotel room where Rommie and Kim are meeting. Rommie tries to act as if she and Kim are having an affair, but the guards do not believe it. Rommie takes the guards out in a firefight. She absorbs several hits, but they do not seem to affect her. She grabs Kim, and jumps out of the window, using an anti-gravity harness to break their fall. When they land, Kim realizes that she is an android, and begs her not to kill him.

Carter, the leader of the security team, also realizes that Rommie is an android.

With Tyr monitoring their communications from the Maru and relaying information to Rommie, she is able to avoid the security search teams. However, the military detects the Maru, and attacks. The Maru is hit, and begins to sink. With the Maru damaged, Rommie has no way to escape. In the stress of the situation, Harper is taking more of his medication than he should be.

Kim shares some of his information with Rommie. He says that he helped design the Basilisk, but he only expected it to be used to defend the planet, not attack others. However, he does not think that destroying a planet full of "AIs and their supporters" is such a bad thing. He says that helping an AI (as he is doing now) would be considered high treason. After the fall of the Commonwealth, AIs were placed in control of Machen Alpha, which worked well, until "logic took over" – e.g. in times of famine, the AIs would kill the sick and the old to minimize the drain on the food supply. Eventually, the people rebelled, and forced the AIs off-world.

The Maru continues to sink, and loses contact with both the Andromeda and Rommie. With the Basilisk moving to attack, Dylan is forced to abandon the Maru to protect Mobius.

Rommie is concerned about those on the Maru, and Kim is amazed that she is acting human.

Tyr suggests that they abandon the Maru and swim to the surface. Rev, however, notes that they are already too deep. He and Tyr, with hardier physiologies, may be able to survive the attempt, but Harper will definitely die. He trusts Harper's ability to fix the ship in time. However, Harper has overdosed on his medication, and falls unconscious.

Carter, searching for Rommie and Kim, has received the information that they had a ship waiting. He is attempting to determine where they might have planned to meet it, in hopes of finding them there.

Kim is still reluctant to give his information to Rommie before she gets him to safety, but seeing her concern for her friends sways him – he gives her a data disk, containing a VR file. Rommie checks the file, and is surprised to see that Machen Alpha has an undamaged Magog swarmship, complete with Point Singularity Projector. She concludes that the Machenites are cooperating with the Magog. She asks Kim to take her to the ship itself. Kim protests that the security is very tight, but Rommie thinks that she can get in.

Andromeda's drones destroy the Basilisk's escorts, but the Basilisk returns fire – with its Point Singularity Projector. Dylan, Beka, and Andromeda conclude that the Magog are providing the technology in order to set the worlds against each other to soften them up for the arrival of the Worldship. Dylan, therefore, no longer feels any obligation to hold anything back.

Rev and Tyr are unable to fix the Maru underwater, but it is continuing to sink. Rev comes up with a plan: use the EVA suits, flood the Maru with water, and use the air circulation system for propulsion. Unfortunately, they find that there is only one EVA suit on the ship. Rev declares that he can survive long enough for them to reach the surface, but even Tyr's Nietzschean physiology is not enough to guarantee his survival. Tyr claims the suit for himself, which will leave Harper to drown.

Rommie is planning to take the swarmship from the Machenites. She gives Kim a forcelance, but Carter's agents attack. Rommie takes them out, but Kim is killed in the firefight.

Rommie's analysis of the building where the swarmship is kept yields little chance of success. Looking for an alternative, she gains access to the reactor controls.

Rev refuses to help Tyr if it means sacrificing Harper. Tyr claims that Harper is suffering from the Magog infestation, so it would make little sense to save him at Tyr's expense. He also claims he could simply shoot Harper, and make the choice academic. Rev notes that, while he could shoot Harper, he has not done so yet.

Andromeda attacks and destroys the Basilisk. They divert the point singularity bullets that were already heading towards Mobius by opening slipstream portals in their path. The slipstream portals cause disruptions on the planet, but they save it from destruction. They then return to Machen Alpha, hoping it is not to late for Rommie and those on the Maru.

Tyr relents, and gives Rev the EVA suit to put on Harper. He says that he will allow himself to drown, and count on the hypothermia and his Nietzschean physiology to preserve his brain function long enough for Rev to revive him when they reach the surface.

Carter contacts Rommie via the VR matrix, and finds her initiating a reactor overload and shutting down the power grid, communications, etc. She says that she accepts the possibility of casualties, and kicks him out of VR.

The building where the swarmship is stored is being evacuated as Rommie moves in, with Carter in pursuit.

With Harper in the EVA suit, Tyr strapped to a bed, and Rev at the controls, the Maru is flooded.

As Rommie and Carter fight, she discovers that he is, in fact, also an android. He stayed on Machen Alpha after the revolution to try to atone for the past. He believes that Rommie will destroy Machen Alpha after she takes the ship, because it is the logical thing to do, and she cannot convince him otherwise. In the end, Rommie destroys Carter with an overloaded forcelance, then she shuts down the reactor to prevent it from overloading.

With the Maru on the surface, Rev revives Tyr just as Rommie arrives in the swarmship to tow them back to the Andromeda. Harper tries to express his gratitude to Tyr for saving him, but Tyr does not want to hear it.

For her success on the mission, Dylan gives Rommie a medal – the Order of the Vedran Empress.