After a rare gem is stolen from an exhibition at a posh hotel, Inspector Farraday decides to recruit former thief Boston Blackie to find the stone. Along with his assistant, "The Runt", Blackie focuses his investigation on the hotel manager, George Daley, and his sister, Eileen. Through disguises and ruses, Blackie and the Runt try to trick their way to discovering the thieves.

Chester Morris
as Horatio 'Boston Blackie' Black

Janis Carter
as Dorothy Anderson

William Wright
as Paul Martens

Richard Lane
as Inspector Farraday

George E. Stone
as The Runt

Robert B. Williams
as Matt Healy

Mark Roberts
as George Daley

Dorothy Malone
as Eileen Daley (Uncredited)

Joseph Crehan
as Jumbo Madigan (Uncredited)

Ben Taggart
as Traffic Cop (Uncredited)
CinemaSerf
To help raise funds for the war effort, a collection of jewels is being displayed at a posh hotel. That's manna from heaven for a thief and when the famous "Blue Star of the Nile" diamond goes walkabouts and "Blackie" (Chester Morris) is found in the vicinity, well then what else might "Insp. Farada...