The ship has just passed through a solar fog and the crew have to investigate a supposed "alien" on board the ship, but are surprised to find that it's a cat that Tycho had been hiding away for the last two years. The crew is divided over whether to keep the cat or follow protocol and euthanise it, but Mara, who has been suffering from a bit of home sickness after talking with her grandmother, convinces the crew that keeping the cat as a pet would be a good idea. Afterward, the ship's computer begins glitching due to the solar fog and they have to try and download new software from Earth.

Pancha discovers that, since the software fix, she now has a strange telepathic connection with Star Runner's computer and she detects a system failure the computer failed to pick up. Leonella discovers that her boyfriend from Earth, Jarrax, has moved on and is going out with Leonella's best friend on Earth, Drina. Tycho and Cinnamon want more responsibility and want to make different smells come out of the air conditioning system.

The cryon that Degenhardt chose to reanimate in place of Dr Flickadello is a fifteen-year-old girl called Zandie. The crew suspects a fault in the computer system, but Pancha knows what Degenhardt did. Meanwhile, Leonella experiments with gene-splicing flowers that will survive Star Runner's artificial gravity.

Mara is given the chance to be in an interview that will be broadcast all over Earth, and she is worried that she might muck up the interview, and humiliate herself in front everyone on Earth. Tane is angry because Mara gets chosen to be in the interview, and not himself. Meanwhile, Leonella is continually frustrated with her mother as she believes she is meddling in her and Tane's relationship, but she's offered help by the most unlikely person.

Zandie receives holophone credits to talk to relatives and friends back on Earth, but she has no one to talk to as all of her friends are New Settlers. Mara runs out of her credit ration while talking to her sick gran, so Zandie gives her credits to Mara. Meanwhile, Sheng uses the holophone to talk to the supposed Amber Lee, Pancha's secret alter ego. Pancha reveals this to Sheng shortly after, and they both reveal their feelings toward each other. Also, Cyriax has a feeling something is wrong with the engine of the ship, and orders everyone around angrily. Cyriax eventually orders that the ship be turned around, back to the wormhole.

Cyriax orders Mara to spy on everyone, and tell him when someone is doing something wrong; she reports a crew meeting that Degenhardt is calling about Cyriax's behaviour. Meanwhile, Pancha and Sheng are having trouble with their relationship, so Pancha creates a timetable for when she can see Sheng and when she can see the computer. Later, the adult officers are ordered by Cyriax to not attend the crew meeting, where he angrily yells at Mara as a disgrace for trading holophone credits. Mara's gran gets more ill, and she feels lost. She decides to resign from the mission, asking Lillian for help, but as they confront Cyriax, he takes a turn for the worst.

Degenhardt hears Cyriax say something about BACKUP 397, so he, Pancha and Mara search the computers to find out what it could mean, disobeying Steve's orders. Leonella and Tane are chosen to take Cyriax back to Earth. Cyriax is loaded on to the escape pod, and Tycho asks for Squirt to be sent back to Earth too. Meanwhile, Degenhardt and Mara check the final 397 thing they can think of, and try the cryon pods. They discover pod 397 supposedly has no one inside, but when they open it, they find Cyriax is in there.

Help from Earth will take two years to arrive at Star Runner, so Tane has a brilliant idea, but it fails. Tycho, Cinnamon, Zandie and Sheng throw a party for C2, who creates a name for himself – "Will Power". Will decides he wants to go back to Earth and before he leaves he uses Tane's idea yet again to unhook the barge from the ship, which creates a huge explosion. Luckily, everyone gets out safely. The ship heads toward the Andromida Line, a point of no return. If they face any troubles after this line, there's no going back.

Steve, Tane, Mara and Degenhardt explore the ship, Infinity, which is seemingly abandoned. All of its crew had been put into suspended animation, and the answer to why lies in the corrupted log left by Commander Darius. Degenhardt and Mara discover a crew member is roaming around the ship when they open a pod and no one's inside. Mara find Tane, who had wandered off, and as they leave a room, a dark figure emerges from the shadows.

The missing crew member, Julian Strega, is found after he falls from an upper level and knocks himself unconscious. He wakes up shortly after on the Star Runner, telling how the Infinity was hit by an asteroid which forced them into a nearby wormhole that wound them up in the Sargasso Disc. However, Leonella suspects that Strega and Tane know each other; she finds a communication log of Tane secretly talking with Strega who was in big trouble on the Infinity.

Tane reveals to Leonella how he and Strega were friends, and how he saved his life. Over on the Infinity, Karen discovers that someone had plotted it on a collision course with the asteroid. Degenhardt and Lillian discover that Commander Darius' pod, and all other crew pods, have been booby-trapped. Sheng develops a program to decrypt Darius' log and, after battling Strega in a computer war to protect the decrypted log, Darius' log is presented to Cyriax, and Leonella confesses Tane and Strega's friendship.

Degenhardt attempts to circumvent the booby-trap on the Infinity crew's pods, but a full reanimation of all cryons is triggered: the Star Runner crew have less than an hour and the only one who can stop it is Strega. He agrees to go to the Infinity with Tane to stop the reanimation, but the countdown was a ruse. Strega locks Tane out of the bridge and turns the ship towards the centre of the Sargasso Disc, claiming to be able to fix everything by travelling back in time.