The famous detective and his trusty side-kick, Tinker, are called in by the War Office to find some important papers that were stolen from a man killed during an air raid.

David Farrar
as Sexton Blake

Manning Whiley
as Raoul Sudd

Dennis Arundell
as Johann Sudd

John Varley
as Tinker

Betty Huntley-Wright
as Nobby

Gordon McLeod
as Inspector Venner

Kathleen Harrison
as Mrs. Bardell

Cyril Smith
as Belford

Magda Kun
as Yvonne

Ferdy Mayne
as Slant-Eyes