During World War II, Captain Cassidy and his crew of submariners are ordered into Tokyo Bay on a secret mission. They are to gather information in advance of the planned bombing of Tokyo. Along the way, the crew learn about each other as they face the enemy and some of them lose their lives.
| Actor | Role |
|---|---|
 Cary GrantCaptain Cassidy | Captain Cassidy |
 John GarfieldWolf | Wolf |
 Alan Hale'Cookie' Wainwright | 'Cookie' Wainwright |
 John RidgelyReserve Officer Raymond | Reserve Officer Raymond |
 Dane ClarkTin Can | Tin Can |
 Warner AndersonAndy | Andy |
 William PrincePills | Pills |
 Robert HuttonTommy Adams | Tommy Adams |
 Tom TullyMike Conners | Mike Conners |
 Faye EmersonMrs. Cassidy | Mrs. Cassidy |
 Peter WhitneyDakota | Dakota |
 Warren DouglasLarry | Larry |
 John ForsytheSparks | Sparks |
 John AlvinSound Man | Sound Man |
 Bill KennedyTorpedo Gunnery Officer | Torpedo Gunnery Officer |
 Eleanor ParkerMike's Wife on Record (voice) (uncredited) | Mike's Wife on Record (voice) (uncredited) |
 Whit BissellYo Yo (uncredited) | Yo Yo (uncredited) |