As you might've guessed, Garp's car collided into Michael's. The accident must've been bad, because the family is now staying with Jenny at Dog Head's Harbor.
Duncan lost his eye in the accident—it "was gouged out" by the "uncovered tip of the stick-shift shaft" (14.3). Ouch.
Helen was giving Michael oral sex when the impact happened, so she broke two teeth, strained her neck, and needed stitches in her tongue.
But that's the least of it—the collision was so powerful that she accidentally bit off "three quarters of Michael Milton's penis" (14.6). Ha.
Garp also sustained some injuries: His jaw was broken and tongue torn up, preventing him from speaking.
Duncan, though bed-ridden, manages to find the bright side of his injury. It sparks an interest in art—he now wants to be a photographer or painter.
It takes Garp a while to finally interact with Helen. He sends her a series of notes, saying that he doesn't blame either of them and that "only in this way can we be whole again" (14.28).
The experience fosters a bit of empathy within Garth, and he even manages to have good interactions with Ellen Jamesians—after all, he has to use notes to communicate now, too.
One day, Garp returns to the facility to find a group of police officers with the young hippy of Mrs. Ralph fame in tow. Apparently the kid's told them he's staying with Garp, so luckily for him, Garp lets him stay.
The hippy's name is Randy and he's actually a huge fan of Garp's work. He stays with them for a while but Garp never gets comfortable with him.
Garp starts writing, although his memory of the recent accident keeps him from delving in too deep. By summer, however, he finally gets underway on his next novel: The World According to Bensenhaver.
The Fletchers visit for about a week. They've had a kid since we've seen them last. It's actually a good visit for everyone involved: Harrison "provided Helen with a confidant" (14.152), and Alice convinces Garp to start speaking again. Go team.
One night, after the Fletchers have been gone for some time, Helen comes to Garp's room late at night. They hear someone taking a bath upstairs, which makes them reminisce about how Walt "liked to lie with his ears underwater" (14.163) during a bath. Wait, where has Walt been?
Helen tells Garp that she wants another child—but she hopes that it's a girl because there could never be "another Walt" (14.187). Oh no…
After the accident, it took Garp a few moments to realize that there was an "absence of sound" (14.204) coming from Walt. He was killed instantly.
Garp and Helen make love for the first time in a long time.