Newly arrived environmental specialist Paula Hernandez finds slotting into place with the rest of the Unity team is harder than she expected after her over-curiosity triggers a bomb left behind by her mysterious predecessor.
A visiting journalist uncovers the background to an aborted space mission, as Paula begins her sexual pursuit of Dusan, and Harry has some startling news.
A primitive Martian life-form demonstrates lethal characteristics when taken aboard Unity. It manifests itself as an acrylic-eating virus and threatens the very structure of the station.
Harry's cat seems to have disappeared, and while she is searching for it, she experiences some difficulties surrounding her pregnancy.
A visitor has a personal agenda, which involves the destruction of Unity when his child prodigy, a member of the crew, appears to have turned against him.
A group dynamics expert exposes cracks and resentments in the crew by purposely digging into their privacy and provoking arguments and confrontations.
A wandering space object creates a supernatural environment when it enters the station. The crew are faced with a First Contact situation of the most unorthodox kind as they suffer bizarre dreams which force them to relive elements of their respective pasts.
A devious entrepreneur utilises Unity as a platform from which to perform somewhat questionable space burials for the benefit of new television audiences.
Crew discipline slides when Kathryn takes ground leave and Shannon is left in charge. An experiment in pheromones results in Paula attempting the seduction of an increasingly distant Dusan.
Desperate circumstances aboard a stricken mining vessel result in madness and cannibalism to stay alive after being lost for three years. The survivors are rescued by Unity and attempts must be made to uncover the truth.
A laser, designed to zap space junk, malfunctions resulting in chaos aboard Unity. Shannon's poor health raises concerns with Paula. While tensions aboard Unity climb, Harry, Lyle and Commander McTiernan are unable to be awakened from an induced sleep experiment. Kaveh and Dusan ignore Paula's concerns, and as a result Shannon's health deteriorates resulting in a stroke.
Abandoned stealth armoury is accidentally reactivated by one of Shannon's probes and it identifies the space station as a hostile entity.
The various personal problems of Unity's crew have been driving them apart, but the occasion of the first child to be born in space brings a return to harmony...eventually.
A solar flare results in chaos aboard Unity as Paula’s relationship with Dusan continues unabated, and Shannon’s poor health raises concerns with the commander. While Unity breaks down around them, Harry and Lyle are unable to be awakened from an induced sleep experiment.
The arrival of a maintenace shuttle brings an unexpected visitor, Anderson from the failed Clementine mission. Commander McTiernan is concerned as the details surrounding Anderson's mission are vague and his shuttle is registered to a nonexistent company.
Harry returns to the station around ten months after her departure with her baby, Miranda.
Harry and Lyle come to terms with the new hierarchy in the science section. Meanwhile, the lives of the Unity crew are put in danger.
Solar flares are casing havoc aboard Unity. A cargo freighter docks with Unity and has two stowaways aboard.
A shuttle hit by a meteor crashes into Unity. While crew of Unity have the grim job of recovering the corpses and their personal effects from the shuttle, strange and unexplained events begin happening around the space station.
CALUM is brought to Unity by Professor Jarvis to replace the station's mainframe. In control of the station, CALUM suddenly becomes sentient. Just as quickly, however, it begins to break down, jeopardizing the safety of the station.
The world's last live specimen of the smallpox virus is being transferred to Unity for ""safe"" keeping. Lyle has an crisis of ethics on whether to let such a deadly thing survive. Meanwhile the crew begin to fall ill and it seems their worst fears have come to life.
Walter, Kaveh, Paula and Dusan discover an orphan, Orla, aboard an abandoned space platform.
Silver Bullet, a project that gives hope for a cure to leukemia. The project is placed in danger, primarily due to Harry's cat and a hybrid plant.
It is the Unity's fifteenth anniversary, and the crew are given a day off to celebrate.
Earth is devastated after a nuclear explosion causing a deadly disease break-out. The crew of Unity begin to experience friction among themselves as a result.
The future of Unity station looks bleak, due to a soon-to-be launched new space platform, named Hyperion.
Unity's fate has been decided, it will be turned into a hotel/casino facility. Tempers flare among the crew as they contemplate their uncertain futures.
