Chapter 20 Summary

On their walk, Trillian thinks she notices movement out of the corner of her eye, but sees nothing. She is distracted from thinking about this when the group comes upon a large crater made by the impact of the sperm whale that had once been a missile. Zaphod is excited, because he notices that the impact had broken open the planet's crust to reveal an underground network of tunnels. They decide to go in, leaving Arthur out to stand guard with Marvin, the paranoid android. Marvin turns himself off, and Arthur is left more or less alone.

As the three others make their way through the tunnels, Zaphod reveals to Ford that he doesn't really know what he's looking for. Zaphod says he gets ideas to do things, not knowing why, and it always works out, even though he doesn't plan very well...