After a long journey, the last man on earth arrives in a destroyed Europe. The only form of life he finds are a few rats in a laboratory. He also finds the remains of Lehman, a mummified old scientist, still sitting at his desk. On top of it he finds an old book written by hand, describing the activities and goals of the lab: to actually inject the entire, inherited guilt of mankind into the rats. The rats travel between stations and pass by various symbolic expressions of human life and human destruction.

The last man studies the book, and tries to continue the experiments as best as he can. But it's doomed to fail as the debt of mankind is great indeed. The last man begins hallucinating about naked women and has thoughts of reproduction which he realizes is completely impossible.

When the symbolisation clarifies, and exposes itself as an old human and religious delusion woven around mystification, well, then the last man gives up. He lays himself down to die, although with one comforting thought: everything must begin again, from the beginning, and next time things will end in a better way. "I walk into the void with my dear illusions beside me."

There's an episode of "Krall" inwhich rats travel around by train. The Rat Trip is partially an expansion on this, and is usually screened in conjunction with "A Streetcar to the Sea". Even though the two films have platonic differences they both share something of the same theme.