As the Germans drop explosive booby-traps on 1943 Britain, the embittered expert who'll have to disarm them fights a private battle with alcohol.
| Actor | Role |
|---|---|
 David FarrarSammy Rice | Sammy Rice |
 Kathleen ByronSusan | Susan |
 Jack HawkinsR.B. Waring | R.B. Waring |
 Leslie BanksCol. A. K. Holland | Col. A. K. Holland |
 Michael GoughCapt. Dick Stuart | Capt. Dick Stuart |
 Cyril CusackCpl. Taylor | Cpl. Taylor |
 Milton RosmerProf. Mair | Prof. Mair |
 Walter FitzgeraldBrine | Brine |
 Emrys JonesJoe | Joe |
 Michael GoodliffeTill | Till |
 Renée AshersonA.T.S. corporal | A.T.S. corporal |
 Anthony BushellCol. Strang | Col. Strang |
 Henry CaineSgt. Maj. Rose | Sgt. Maj. Rose |
| JJames DaleBrigadier | Brigadier |
 Robert MorleyThe Minister | The Minister |
 Sidney James'Knucksie' Moran | 'Knucksie' Moran |
 Sam KyddCrowhurst | Crowhurst |
 Geoffrey KeenPinker | Pinker |
| JJune ElvinNot listed | Not listed |
| RRoddy HughesWelsh Doctor | Welsh Doctor |
 Bryan ForbesPeterson | Peterson |
 Roderick LovellNot listed | Not listed |
| EElwyn Brook-JonesNot listed | Not listed |
| JJames CarneyNot listed | Not listed |
 John StrattonYoung Army Officer | Young Army Officer |