Rhode's novel is centered around the great annual motor rally at Torquay. Robert Weldon takes part in the rally hoping to win a prize driving his 20 h.p. Armstrong Siddeley Saloon. Accompanied by Richard Gateman as the second driver and Harold Merefield as the map reader, he begins well. But on the second day, their luck turns. First they are waylaid by a fog and then in the dead of the night they come across another car from the rally which has met with an accident, killing both the driver and the man accompanying him. The coroner returns a verdict of death due to accident (and the coroner inquest is narrated in the most humorous manner) but then an astonishing fact comes to light and it is left to Dr. Priestly who is the employer of Merefield to solve the case.