The film depicts an account of Allied Combined Operations Headquarters commandos executing a daring raid on the German-occupied French coast during the Second World War. The story is based on the commando raid on the French port of St. Nazaire.
| Actor | Role |
|---|---|
 Lloyd BridgesMaj. James Wilson | Maj. James Wilson |
 Andrew KeirCapt. Owen Franklin | Capt. Owen Franklin |
 Sue LloydSue Wilson | Sue Wilson |
 Mark EdenLt. Cmdr. Donald Kimberly | Lt. Cmdr. Donald Kimberly |
| MMaurice DebhamRear Adm. Sir Frederick Grafton | Rear Adm. Sir Frederick Grafton |
 Glyn OwenForrester | Forrester |
 Howard PaysLt. Graham | Lt. Graham |
 Walter GotellVan Horst | Van Horst |