"An engineer leads the building of a trans-Atlantic tunnel linking Britain and the United States."
Richard Dix
as Richard 'Mack' McAllan
Leslie Banks
as Frederick 'Robbie' Robbins
Madge Evans
as Ruth McAllan
Helen Vinson
as Varlia Lloyd
C. Aubrey Smith
as Lloyd
Basil Sydney
as Mostyn
Henry Oscar
as Grellier
Hilda Trevelyan
as Mary
Cyril Raymond
as Harriman
Jimmy Hanley
as Geoffrey McAllan
George Arliss
as Prime Minister of Great Britain
Walter Huston
as President of the United States
Maurice Elvey
Director
Marianne
Wardrobe Designer
Curt Siodmak
Screenstory
Bernhard Kellermann
Novel
L. du Garde Peach
Scenario Writer
