"The Shrieking Pit" – American detective Grant Colwyn is spending his holiday in England when it is brought to his attention the strange behavior of a fellow guest. A well known doctor, Sir Henry Durwood, claims that the young man is suffering from a rare form of epilepsy and may soon present a danger to other hotel guests. The strange young man leaves hotel the next day and finds a lodgings in a nearby inn, but soon after that a murder is committed in a neighboring town, and the same young man is the only suspect. Although all the evidence points to him as the murderer, Grant Colwyn believes in his innocence and sets out to prove it.
"The Hand in the Dark" – Mrs. Meredith has invited all her friends from her freer, wilder life in London to meet with her at her husband's family home in rural Sussex. However, she is seemingly taken ill and can't accompany the party on their final jaunt to a neighbor's house after dinner. Her husband, step-sister and friends sit down for dinner just before departing when they hear a scream from Mrs. Meredith's room, shortly followed by the gun shot. The household ascends the stairs to find the young wife murdered, shot from close range. The case is being investigated by a duo of Scotland Yard inspectors who meet a dead end, and the famous private detective Colwyn will have to offer his point of view.