Sent to find the Ultimate Question to Life, the Universe and Everything, Arthur Dent and his companions have been cornered by two humane cops who, nevertheless, have left them in a certain-death situation.

Arthur, Ford, Zaphod and Trillian discover that the explosion caused them to travel forward through time. They are at Milliways: The Restaurant at the End of the Universe. Here, they wine and dine whilst all of creation is destroyed around them.

Zaphod then gets a telephone call from Marvin, who has been waiting for his return for several billion years. Everyone meets up in the car park, and they steal a space ship which is totally black.

As everything in the ship is black, they cannot control it. During the voyage, Marvin claims that he is able to tell what the Ultimate Question is by reading Arthur's brain wave patterns. However, they are distracted when they discover that they are going backwards through time, at which point they discover that the ship they stole is at the head of an intergalactic battle fleet.