Zaphod Beeblebrox and his mysterious friend Roosta are being taken in a flying building to the evil Frogstar, whilst Ford Prefect and Arthur Dent are stranded on prehistoric Earth. Some of them are getting hungry.

On their way to the Frogstar, Roosta tells Zaphod that he is to be fed into the 'Total Perspective Vortex', the greatest torture a sentient being can face.

Back on pre-historic Earth, Arthur and Ford decide to wave Ford's towel to attract the space ship. In doing so, the ship crash lands onto the planet. The towel lands in some lava caused by the crash, is fossilised and is picked by the Improbability Drive after the Earth is demolished. What is more, Zaphod is driving, having survived the Total Perspective Vortex.

Zaphod then goes on to tell the story of how he managed to survive the Total Perspective Vortex, in which he sees the entire universe and himself in relation to it, and discovers his ego is as big as the entire universe.