Back in New York, Martin and Joyce go to dinner with Dr. Holabird and his wife. Holabird announces that Martin is going to become the Assistant Director of the McGurk Institute, and that he'll become full Director when Holabird leaves, which will happen within the next few years.
Everyone at the dinner table is super excited except for Martin. He saw what being director did to Max Gottlieb and he doesn't want to go down the same path.
Afterward, Martin gets into a big fight with Joyce about whether he should take the job.
Early the next morning, Martin packs two suitcases, leaves a note, and takes off for Vermont to be with Terry. And the truth is that he lives there in total happiness, left with nothing to do but work.
Joyce sends him a note saying that if he ever plans on coming back, he'll have to be the one who begs forgiveness. She's too proud to come chasing after him. He never comes back (or even sends a letter), though.
Eventually, Joyce caves and goes after him. He holds firm on his decision, no matter how much she tries to guilt him into coming back and taking care of their son. The truth is that Martin is a total fanatic by this point. He doesn't even like showering because it takes time away from his work.
The book closes with a short description of what all the characters in this book are doing.
Dr. Pickerbaugh is having dinner in Washington.
Max Gottlieb is muttering to himself in German in a lonely armchair.
Joyce is talking to a man named Latham about how the two of them can get married as soon as she divorces Martin.
Meanwhile, Martin is working with Terry on their experiments. He thinks that everything they've worked on for the past year might be a dead-end, but he doesn't care because he's truly happy.