The search for a runaway girl leads Father Brown and his friend Flambeau to a struggling theatre company, replete with backstage gossip, ambitious actors, tempermental divas, mysterious visitors, and murder.
After a rash of robberies, the evidence implicates a gentle beekeeper as the notorious jewel thief whom the press has dubbed Michael Moonshine. Father Brown keeps faith in his friend, however, and unmasks the real murderer.
When wealthy collector Brander Merton buys a Coptic chalice, he doesn't intend to meet the same fate as the relic's two previous owners. But after an arrow strikes him dead, Father Brown must expose the cup's supposed curse.