The ship lay buried, frozen in the ice of an "astro-glacier", for three million years until the crew of Starbug discovered it. Kryten noted with the Psi-Scan that her engines were dead due a power overload, as though they had been fleeing from something (it is revealed later that the Leviathan was actually trying to reach Delta VII in the hope of a cure for the Epideme virus). They found no sign of life except from a block of ice that has a woman frozen within. The woman, Caroline Carmen, was once a supply officer on Red Dwarf.
After being infected by Epideme, Lister straps explosives to himself and returns to the Leviathan, where he plans to destroy himself and the virus. But he discovers something in their computers: the crew of the Leviathan was close to eradicating the virus themselves. They were heading for the planet Delta 7, but crashed before they got there. He returns to Starbug to see if they can make it there in time. ("Epideme")
- The navicomp of the Leviathan is briefly seen, just as Lister stops the TNT detonation. The readout shows it's path to Delta VII, and also suggests that it's home base of call was a planet called "Theta 4".
- Whereas almost every other spaceship seen in the show has an "SS" in front of it, the Leviathan is never stated as having such a prefix. This is maybe because most starships seen in the show were of the Space Corps, and the Leviathan was of the JMC. Similarly Red Dwarf itself had no such "SS" prefix, and was also of the JMC.
- The external hull of the Leviathan is never seen, since it is buried in the space iceberg. Although Starbug is able to dock with one of it's exposed airlocks, allowing the Dwarfers to enter, only the interior of the ship is seen. However the navicomp readout would seem to suggest that it was "frisbee"-shaped, like the SS Manny Celeste.