A group of scientists are developing a secret hypersonic plane but tensions rise when the team leader has a suspicious fatal accident and emotional relationships get complicated. Despite looking for a traitor the acting is very flat and the filming very dark, but the few shots of the plane are the best parts.
2/5 
Phyllis Calvert
James Donald
Robert Beatty
Herbert Lom
Muriel Pavlow
Noel Willman
Walter Fitzgerald
Maurice Denham