It's the summer of love in late 1960s England. Astronauts are preparing to land on the moon, the war in Biafra dominates the news and Basil D'Oliveira has just been dropped from the England cricket team. In the midst of all this change, Sidney Chambers continues his amateur sleuthing investigations.
A bewitching divorcee enlists Sidney's help in convincing her son to leave a commune; Mrs Maguire's husband returns from the dead; and an arson attack in Cambridge leads Sidney to uncover a cruel case of blackmail involving his former curate. In the rare gaps between church and crime, Sidney struggles with a persistent case of toothache, has his first flutter at the Newmarket races and witnesses the creation of a classic rock song.