Chapter 13 Summary

Marvin, still depressed and complaining about everything from the doors on the ship to the dullness of his life, brings Arthur and Ford to the bridge. Ford introduces Zaphod as his "semi-cousin," but Arthur doesn't need an introduction -- he too already knows the man. He tells Ford that Zaphod came to an Earth party in London and asked "a beautiful, charming, devastatingly intelligent" girl if she was bored with Arthur and wanted to talk to him instead. That girl was named Tricia McMillan, and Arthur discovers, as Trillian now moves into his line of sight – the two women are one and the same. Trillian explains that she had hitched a ride with Zaphod just as Ford and Arthur had. Just then, the computer interrupts with the (finally) completed Improbability sum. "Infinity minus one," the computer determines. Zaphod, stumped, asks Trillian if this...