A circus barker stages a sensational new act, the world's longest fast undertaken by “Sapolio”, on view in a glass cage. But this act also results in several murders, a kidnapping, and a poisoning!
A rich but disliked elderly man invites his relatives to a family reunion at his home. Once the gathering is complete, he announces enigmatically that he intends to change his will before he dies. Before he can do this, he is murdered. His niece (Gynt), a detective story writer, has to put her theories into practice by solving a real-life murder mystery.
A pair of reporters try to discover the link between three unsolved, seemingly isolated murders. The only connection between them is they all took place on the same day in three successive years. The police don't trust their instincts - but as 10th July nears again, a solicitor has started receiving threatening letters...
