Sarah and Gemma appear in a flash on a very brightly lit spaceship with white walls. They are initially treated with suspicion and locked in a cell. The guards say they must be the bounty hunters they have been warned about, who are coming to capture their captain, Princess Gloriana, and hand her over to the enemy. The Princess (Danny La Rue in outrageous drag) tells her crew that the threat is over. Meanwhile, a crew member examines an egg-like object. It bursts open and sprays shaving foam all over his face. He collapses.
Inept bounty hungers Nigel and Sharon lurk in another part of the ship, discussing their plans. Both have huge hair and are dressed like Dexys Midnight Runners in 1982, even though this story was made in 1985. Nigel has doubts, but Sharon says it is the perfect time to strike.
Sarah uses her psychic powers to persuade a guard to let her and Gemma out. They sneak away and see Nigel and Sharon going into the engine room. The headless corpse of the crew member is found next to the egg. As the crew wonder what happened, the engine stops. Sarah and Gemma see Nigel and Sharon come out of the engine room, smash the door controls, and then slip away. Sarah tries to fix the controls but the guards along and think she is the saboteur. Sarah and Gemma are locked in the cell again, despite their protests.
Two crewmen trying to get into the engine room are attacked by an unseen monster. Their headless bodies are found soon afterwards. Sarah and Gemma are interrogated but Sarah insists that they couldn’t have killed anyone while they were locked up. Gloriana accepts this and they are left in the cell. She orders the guards to search the ship. A bigger ship is detected on the scanner but is out of visual range.
Sarah uses mind control on the guard again but senses something wrong. The door opens to reveal a rubber jellyfish-like alien stuck to his head. He falls to the floor and the alien flies off the headless corpse towards Gemma, who screams.
Sarah uses her powers to distract the alien while Gemma grabs the guard’s gun and shoots it. They run out of the cell.
A large enemy ship appears on the screens. It’s crew stand in the dark, and only their hands are seen. The enemy admiral, Klype, tells his cringing henchman to prepare a boarding party. The henchman says they are out of range. The admiral insists on going faster.
Back on the white ship, Gloriana says the engine room door must be blown open, but the crew are too scared to go down there. Sarah finds the bodies near the engine room and tells Gemma it’s worse than she thought. Gemma tries to shoot the door open but it doesn’t work.
Nigel and Sharon are attacked by an alien but Sharon kills it. Guards patrolling the ship are picked off one by one and the aliens keep multiplying.
Sarah and Gemma get to Gloriana and say they want to help. She agrees because the situation is so desperate, and orders the guards to look out for Nigel and Sharon.
Nigel radios the enemy ship to say that there are aliens on board. The admiral decides to give up on boarding and just open fire when they come into range. His henchman gives excuses for why they aren’t in range and can’t go faster. Nigel suddenly comes into shot with an alien on his head. Sharon runs off, screaming in terror.
Everyone on the bridge, even Sarah, gets guns. They fight their way to the engine room and blow the door in. Gemma takes charge of the defence as the crew fix the engine. Sarah points out that with the door irreparable, the engine will vaporise every living thing when it starts (even though no-one was vaporised when it was running before). Gloriana says they will have to seal themselves in the bridge. Sharon hears this from where she is hiding but can’t get to them.
The enemy ship is almost in range. Admiral Klype says, “prepare to fire”. Everyone but Sharon gets back to the bridge, and the blast doors are sealed. Gloriana switches on the engine but nothing happens. Sharon, still in the engine room, sees a loose connection and goes towards it. Aliens chase her and surround her. She completes the circuit, making herself and the aliens explode into tiny pieces thanks to Quantel Paintbox. The ship speeds away, and the admiral is furious at his henchman.
SHARON: Nigel, you wally.