At age 60, disillusioned with academia and estranged from his family, retired historian Gerald Middleton looks back on the summer of 1912. Then, as a young man, he witnessed the discovery of a phallic idol in the excavated grave of a medieval bishop and fell in love with Dollie, his best friend's fiancée.

Over Gerald's objections, Inge invites the conniving Larrie to stay with her at the family estate—unaware that Larrie and her favorite son, John, are secretly lovers. Meanwhile, trying to uncover the truth about the Melpham idol, Gerald visits Professor Portway's widow, Lilian, in France.

With an angry confrontation between Robin and his brother-in-law and emotional entrances by Elvira and Larrie, a soiree thrown by Marie Helene ends in disaster for all three of the Middleton children. Gerald reconnects with Dollie after years of separation and finally learns the unambiguous truth about the Melpham idol.