Hal and Julie Lang host a going-away party for Jack Felton, a family friend off to Europe on a Fulbright. Julie is an industrious court stenographer and avid reader; an adopted orphan who often feels left out. Jack was once known for being a rabblerouser but he is quieter tonight, taken aback by how much everyone has changed since he last saw them. Hal is quietly flirting with Karen Green, his high school crush. The languid summer night has stupefied the party guests, all splayed listlessly around the porch.

The group suddenly hears strains of dance music by the bay, and realize the Legion club is hosting a dance. They walk out to the dock, reminiscing about a friend who accidentally drove her car into the water. Feeling giddy, Jack convinces the others to 'borrow' the dinghies and row out to a tiny island off the shore. When they arrive, Karen and Hal wander off exploring. Karen has the impression Hal will make his move, has, in fact, been feeling for a long time that some man was on his way to her - and despite her marriage, she is indifferent to the possibility.

Jack wakes up on the island utterly alone. The boats are gone; the others have abandoned him. Angry at first, he sits on the dock in the early morning hours, content to have friends who would pull such a prank. Looking back on the night twenty years later, living in Brighton, England, Jack tries to piece together every face that had been brought together at that party. The Langs had parted ways, as had Bob and Susan, each pursued a life that seemed to Jack preordained in their personalities. He walks down from his flat to the sand by the beach, remembering his time on the island.