The novel is about an adult couple who rekindle a long-ago summer romance that ended because of class differences, and their two teenage children from other marriages who also fall in love with each other.

Ken leaves the island for good at the end of the summer, and Sylvia marries Bart as her family wishes.

Ken becomes a millionaire through his work as a research chemist, and marries his partner's daughter, Helen, who turns out to be prudish and frigid.

Helen and her mother Margaret are not pleased, as they find it inappropriate for a girl Molly's age to be so attached to a boy, but the correspondence continues, with rendezvous during school breaks.

Ken and Sylvia give their guarded approval to John and Molly's marriage, feeling it would be hypocritical for them to deny the teenagers their love.

Bart cannot attend the wedding, since his alcoholism has forced him to enter a veterans' hospital; while he disapproves, he urges John to take over the inn.