An escape pod docks with the Dwarf and is carrying the only survivor of a ship which was attacked by a genetically-engineered corrosive life form. Unfortunately, the corrosive material is also on board and begins to eat away at Red Dwarf. Meanwhile Lister tricks Kryten into believing that Kochanski's 'time-of-the-month' is an event to be celebrated and he embarrasses himself in front of her. Plotting revenge, Kryten steals four flagons of illegal alcohol from an inmate and leaves it in Lister and Rimmer's cell just before an inspection. Lister discovers the alcohol and he and Rimmer are forced to drink it before their inspection. They only take one mouthful out of the bottle and are immediately drunk. Meanwhile, the crew learn of the life form destroying Red Dwarf and plan to abandon ship, leaving the prisoners aboard to die.
The gang figure out a way to combat the life form by creating a doorway into an opposite universe and finding the opposite to the corrosive material.