The Siamese twin mystery

About “The Siamese twin mystery”

Ellery Queen and his father are driving through a mountainous area of the United States when a forest fire forces them to take shelter in a private home. The home, owned by Dr. Xavier, is occupied by his family, guests, and several unusual individuals, including conjoined twins, a doctor's assistant who buries strange parcels, and a man who claims to be "Mr. Smith." As the fire approaches, Dr. Xavier and his brother are murdered, each found holding half a playing card. A jack of diamonds suggests only one of the twins is the killer. Ellery and his father investigate the murders while also trying to escape the fire. Ellery deduces the murderer's handedness from the torn cards. The mystery is resolved as the flames reach the top of the mountain.