Lionel Atwill

Dr. Ralph Benson, posing as Graham

Una Merkel

Aunt Margaret Wentworth

Nat Pendleton

Red Hogan

Claire Dodd

Patricia Wentworth

Anne Nagel

Mrs. William Saunders

Hardie Albright

William Saunders

Richard Davies

Jim

John Eldredge

Dwight, Ship's Officer

Mala

Barab

Noble Johnson

Native Chief Elan

Rosina Galli

Tanaa, Chief's Wife

Al Kikume

Kalo

Milton Kibbee

Hadley

Byron Shores

Crandall, murdered detective

Bess Flowers

Ship Passenger