A German submarine is sent to the Orkney Isles in 1917 to sink the British fleet.
Conrad Veidt
as Captain Ernst Hardt
Sebastian Shaw
as Ashington
Valerie Hobson
as The School Mistress
Marius Goring
as Lieutenant Felix Schuster
June Duprez
as Anne Burnett
Athole Stewart
as The Rev. Hector Matthews
Agnes Lauchlan
as Mrs. Matthews
Helen Haye
as Mrs. Sedley
Cyril Raymond
as The Rev. John Harris
George Summers
as Captain Ratter
Hay Petrie
as Engineer
Grant Sutherland
as Bob Bratt
