During a masquerade ball at an English country estate with a valuable collection of artifacts on display there is a shot, the lights go out, and a robbery ensues. It’s soon followed by an entertaining, if unsuccessful, chase of the thief by the costumed revelers.Chief Constable Sir Clinton Driffield’sinvestigation discovers the robbery was planned as a practical joke that has gone awry. There are conflicting clues, unclear motives, and then...