Course Hero. "The Hitchhiker's Guide to the Galaxy Study Guide." Course Hero. 28 Nov. 2016. Web. 15 Dec. 2018. <https://www.coursehero.com/lit/The-Hitchhikers-Guide-to-the-Galaxy/>.
Course Hero. (2016, November 28). The Hitchhiker's Guide to the Galaxy Study Guide. In Course Hero. Retrieved December 15, 2018, from https://www.coursehero.com/lit/The-Hitchhikers-Guide-to-the-Galaxy/
(Course Hero, 2016)
Course Hero. "The Hitchhiker's Guide to the Galaxy Study Guide." November 28, 2016. Accessed December 15, 2018. https://www.coursehero.com/lit/The-Hitchhikers-Guide-to-the-Galaxy/.
Course Hero, "The Hitchhiker's Guide to the Galaxy Study Guide," November 28, 2016, accessed December 15, 2018, https://www.coursehero.com/lit/The-Hitchhikers-Guide-to-the-Galaxy/.
Complaining about life in general and the cheery-sounding doors on the ship in particular, Marvin leads Ford Prefect and Arthur Dent to the bridge. Then, still depressed, he offers to sit in a corner and rust, or fall apart where he stands—whichever suits Zaphod Beeblebrox.
With an air of super coolness, Zaphod greets Ford. Not to be outdone, Ford nonchalantly introduces Zaphod to Arthur as his "semi-cousin," and is staggered by the news that introductions are unnecessary. Arthur and Zaphod already have met, at a party six months ago in Islington. Arthur had been talking to a "beautiful, charming, devastatingly intelligent" girl when Zaphod walked up and asked if she was bored with this guy. He then invited her to talk to him instead, adding, "I'm from a different planet." That was the last Arthur saw of her.
That girl was named Tricia McMillan, and once Arthur sees Trillian, he discovers that she and Tricia are one and the same. Trillian explains that, like Ford and Arthur, she has hitched a lift with Zaphod.
Abruptly, the computer interrupts with the completed Improbability sum describing the unlikelihood of Ford and Arthur's rescue. "Infinity minus one," the computer chatters happily. Clearly bemused by the extraordinary odds, Zaphod asks Trillian if this sort of thing is going to happen every time they use the Improbability Drive. "Very probably, I'm afraid," she replies.
Arthur Dent's first sight of Zaphod Beeblebrox as he and Ford Prefect step onto the bridge reminds the reader that the Galactic President has two heads and three arms. With this meeting aboard the starship, improbabilities multiply. Not only is Zaphod by chance related to Ford, but Arthur met him not long ago at a party on Earth (while he had one less head and arm). The girl Arthur tried to pick up at a party, only to lose her to Zaphod—who called himself "Phil"—turns out to be Trillian, known on Earth as Tricia McMillan.
The chapter reveals that Zaphod's transformation has been relatively recent. He had the usual number of heads and arms just six months ago at the party on Earth. It also affirms what readers have suspected about Trillian, based on her efficiency at running the ship and dealing with Zaphod: She is a highly intelligent, well-educated woman, with degrees in math and astrophysics. Somehow, her presence on the Heart of Gold as assistant to Zaphod, following their casual encounter, seems like another very lucky and improbable coincidence. So far, however, there seems to be a kind of crazy-quilt plan behind events. No matter how unexpected or improbable they may be, they somehow fit together. It's safe to assume that Trillian is present on the ship for a good reason.