Beka and Haper are assisting, in the middle of a storm, with a planetary evacuation, while Dylan is caught in a nearby solar storm in the Maru. Beka and Harper have seen the last ship off, but as Dylan cannot get free to land, they take cover in a cave. Harper twists his ankle and removes his boot to check it out, setting it on a nearby rock. He does not see a maggot or slug-like creature crawl from a nearby puddle of slime and burrow into his boot heel.

Dylan manages to get free of the solar storm, and picks them up.

The three of them are on the Maru, waiting to rendezvous with the Andromeda. Beka is reading a horror novel, and Harper teases her about it, saying that they are not really scary. Beka, however, talks him into reading one himself.

The maggot gets out of Harper's boot, and starts to eat into the ship. An alarm goes off, and Beka rushes to the cockpit. The Maru's sensors have detected an unidentified life form, and she accuses Harper of bringing a "pet" aboard, but he denies it. Further examination reveals that the life form is metallivoric, and has damaged the guidance system. The ship spins out of control, but they are close enough to the Andromeda for her to send out drones to bring them in.

Harper and Dylan find the maggot on the wall of the Maru, and Dylan traps it with a box, but the maggot escapes by eating its way through the wall.

After landing in the hangar, Dylan asks Rommie to use an anti-oxidation field and/or depressurize the hangar to contain the creature, but Rommie warns him that these measures will only be temporary.

Harper plans to build a "box" out of Andromeda's spare hull plating (which is made of carbon microfilament, not metal) to contain the Maru. He does not notice, however, that another maggot crawls out of his boot in the Andromeda's corridor.

While working, Harper tries to get into a secure area, but Rommie denies him access, saying he has to get the code from Dylan. Harper goes looking for his record of ship access codes, but cannot resist picking up the horror novel for "a quick ten pages".

Rommie has determined that there are 68 species of metallivoric parasites in the sector, but they need to catch one in order to identify it.

While Harper is reading, he hears a noise, and the lights start to flicker. He thinks Rommie is trying to encourage him to get back to work when the lights go out entirely. Harper screams, and when the lights come back on, Harper is lying on the floor, grabbing a pair of feet – Tyr's. Tyr tells Harper to get back to work.

On the way to parts storage, Harper meets Beka in the corridor. He tries to convince her to accompany him, but she laughs, teasing him about being scared by the book he is reading.

When Harper enters the parts storage area, the lights are not working properly, so he wedges the door open behind him.

Trance is working in hydroponics, but does not see a maggot crawling among the plants.

Dylan is walking in the corridor, and hears footsteps, making him nervous. Rommie shows up, startling him. She tells him that the containment on the Maru has failed, and the maggots are loose on the ship.

Tyr is lifting weights, when he catches sight of shadows on the wall and the door starts to open and close. He investigates, and finds nothing, but turns back to find his barbell bent almost in half.

The bar that Harper has set to hold the parts storage door open falls to the ground, spooking him. He finds another door opening and closing, and investigates it. He finds an area that he is unfamiliar with, and a hole in one of the walls. When he looks through the whole, a ghostly head appears and scares him away.

Harper tells the others about this "ghost". Dylan wonders if it might be one of the new crew members, but Harper insists it was not someone that he recognized, and crew members do not live in the walls.

Dylan, Beka, and Tyr go to investigate, and when Dylan checks the hole in the wall, he finds more maggot slime.

Rommie uses her sensors to search for maggots on the Andromeda, and finds them all over the ship. Harper suggests using insecticide throughout the ship, but Rommie says that the only poison that would be effective would be corrosive gasses, which would also be hazardous to the crew. They decide to set traps for the maggots throughout the ship, and Harper begins to build bait stations, to the accompaniment of some loud music, and the rest of the crew begins to place them. While doing so, Trance meets the "ghost", who orders her to "get out". She goes to talk to Harper, and tells him that she believes him, since she saw the ghost. While they are talking, Harper's music comes back on, and he has trouble turning it off. The ghost appears on the catwalk above, saying "Dylan must abort his mission!" Trance says that they have to follow the ghost, but Harper is reluctant.

While Beka is setting some traps, the floor collapses underneath her. She falls, but holds on to some wires. The ghost appears, spooking her. She falls, but Tyr is beneath her and catches her.

The ghost appears on Command, and approaches Rommie, telling her to leave, but she does not seem to notice it. The ghost notes, audibly, that she is an AI. Harper and Trance enter Command and see the ghost, but Rommie insists that she does not see it, saying it must be a hallucination and not real.

Rommie tells Harper and Trance that she has detected some emissions from an area that, according to her schematics, does not exist.

Dylan and Beka investigate this area, which Dylan says was a top-secret research area (although he says that it is still strange that it is not found on Rommie's schematics). They find a mech lab, containing a body in a High Guard uniform, trapped under a fallen piece of equipment. The body has a communications device in its hand, containing a recorded message that was not sent. When Dylan plays back the message, it is a recording of the dead crewman, who is also the "ghost", begging for Dylan's help. Dylan identifies him as Eddie Aldritch, who was a new addition to the crew just before Hephaestos. He theorizes that Eddie came through the event horizon alive, but could not be detected because he had hidden the area from the ship's sensors.

Beka, Harper, and Tyr discover that the traps did not work, and they cannot call for help because the communications systems have been damaged.

Rommie and Dylan review Eddie's records. He was a brilliant scientist, with a talent for concealment and misdirection of sensors. He was also a self-centered loner, but apparently considered Dylan a friend (to Dylan's surprise).

Eddie appears to Dylan on the Command Deck. He accuses Dylan of betraying the Commonwealth, staging an invasion to force the crew to leave the ship so he could use it for his own purposes. He says that he is going to "bring him in", but Dylan tells him that there is no one to "bring him in" to – the Commonwealth fell 300 years ago.

Eddie grabs Dylan, and lifts him off the ground. He draws his forcelance, and the two of them struggle over it. Dylan manages to turn the forcelance on Eddie, and fires, revealing (by exposing internal components), that Eddie is an android.

Dylan begs Eddie for help, but Eddie throws him across the Command Deck. Rommie tells Dylan that Eddie has seized control of her systems. He shuts down her AI, and activates the self-destruct sequence.

Dylan sends Beka and the others to the Maru to get off of the ship, while he confronts Eddie and begs him not to destroy the Andromeda. A maggot crawls on Eddie's shoulder, but he electrocutes it, killing it. Dylan tells Eddie that he can save the Andromeda. Eddie asks Dylan if they would have been friends if he had lived, and Dylan claims that they are friends. He asks Eddie to electrocute the ship to kill the maggots. Eddie does so, lifting Dylan off the floor in order to save him. Eddie then collapses.

Afterward, Dylan gives Eddie a proper High Guard funeral.

Harper returns Beka's box of horror novels, saying that he does not want anything more to do with them.