Meanwhile, Marvin leads Arthur and Ford to the bridge, where the two groups of people meet. We can finally stop saying "meanwhile."
Zaphod is totally relaxed, but "Ford was not going to be outcooled" (13.27).
So both of them pretend like this is all totally ordinary: it's totally ordinary to be picked up after being thrown out an airlock.
Unfortunately, they both lose their cool when Arthur claims to know Zaphod. Apparently, Zaphod crashed a party on Earth once—and went by the normal name "Phil." Also, we should note that he had only one head and one arm at the time, which is why it was a boring party.
The party was in Islington. Ah, now we remember that comment about a phone number for an Islington apartment in Chapter 8. Now, at this party, Arthur was trying to talk to a great woman. But then "Phil" interrupted by saying she should come with him since he was an alien.
And guess what? Trillian was the woman at the party. Her Earth name is Tricia McMillian, which is cool but not nearly as space-sounding as "Trillian." By the by, that's also how Shmoop got its name. Its Earth name was Shubert Hinklemoop.
Trillian decided to come to space because what was she going to do on Earth with degrees in math and astrophysics? Wall Street would be our guess these days.