Warner as Captain Maddox Anthony Steel as Lieutenant Geoffrey Ainsworth Robert Beatty as Lieutenant Jim Reed William Sylvester as Lieutenant Texas Norton Anton Diffring as SS Hauptsturmführer Schultz (credited as a Hauptmann, the Heer equivalent in the credits) Michael Balfour as Lieutenant Henry Adams Guy Middleton as Captain Barton Paul Carpenter as Lieutenant Fred Erickson Moultrie Kelsall as Commander Henry Dawson Eddie Byrne as Commander Joe Brennan Geoffrey Hibbert as Lieutenant Cutter Craig Peter Jones as Lieutenant Schoolie Browne Frederick Valk as Camp Kommandant Frederick Schiller as Herman Walter Gotell as Feldwebel Peter Swanwick as Obergefreiter Historical background The film is based on a true story. "Albert R.N." was a dummy constructed in Marlag O, the prisoner of war camp in northern Germany for naval officers. The head was sculpted by war artist John Worsley (1919–2000), the body by Lieutenant Bob Staines RNVR, and Lieutenant-Commander Tony Bentley-Buckle devised a mechanism enabling Albert's eyes to blink and move, adding realism to the dummy. "Albert" was used as a stand-in for a head count while a prisoner escaped and was used on two occasions. In the first attempt Lieutenant William "Blondie" Mewes RNVR escaped from the camp shower block and the skilful use of "Albert" during roll-calls gave him four days head start before a missing PoW was reported. Mewes was recaptured in Lübeck and returned to Marlag camp. The second occasion failed when the escaping PoW was discovered hiding in the camp shower block and "Albert" was discovered in the subsequent searches. Worsley made a new "Albert" for use in the film. Senior Commissioned Gunner (TAS) Lieutenant John William Goble RN aided Worsley in the development of "Albert" in the POW camp, Marlag O and acted as technical adviser for the film. Worsely made a third "Albert" for the retrospective exhibition of his work held in Brighton College's Burstow Gallery. After the show, it was donated to the Royal Naval Museum Portsmouth. Guy Morgan and Edward Sammis, who were British POWs, wrote a play based on the story on which this film was based. This was subsequently adapted into a screenplay. Production The film was first planned as a project for Romulus Productions and star Sonny Tufts (as an American film star), Trevor Howard, Anton Walbrook and Ralph Richardson. Jack Warner and Anthony Steel were both leased to producer Daniel Angel by the Rank Organisation. Both had previously appeared in POW