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 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 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.