Frank Hardy

Tiger Van Dorn

Ralph Marshall

Valerie Shields

Dorothy Elliott

Tom Banning

Lightning

Chiang-Houseboy

Jim Murphy

Inspector Starrett

Robert Banning

Armand Roget

John Charles

Paul Marshall

Campbell

Professor

Mrs. Maitland

Chandler Elliott

Doctor Coleman

Singapore Joe

Joe Nolan

Angus MacLeod

Hardy's Assistant

Henchman

Greenway

Jackson

Roget Clerk #1

Sailor

Undercover Detective at Dive

Detective Interrogating Pete

Peters

Henchman

Henchman