Blackie is the natural suspect when an expensive pearl necklace is stolen while he is supposed to be guarding it.
Horatio 'Boston Blackie' Black
Doris Howell
Insp. William R. Farraday
Joan Howell (as Patricia White)
The Runt
Sgt. Matthews
Igor Borio
Margie O'Reilly, alias Sandra Doray
Mason Carter
Claire Carter
Helen Kenyon
Party guest