Written by Eric Ambler as a cinematic pageant for the 1951 Festival of Britain, this tale of William Friese-Greene, the British inventor who first patented a commercially viable motion picture camera (or did he?), is mainly of parochial interest for the cavalcade of household names. Lord Olivier turns up under a policeman's helmet to stare suspiciously at Donat's - 'But it moved!' - first triumphant screen projection. Then there's (among others) Jack Hulbert, Kathleen Harrison, Margaret Rutherford, Peter Ustinov, Stanley Holloway, Robertson Hare, Emlyn Williams, Ronald Shiner, Cecil Parker and most of the cast of Radio Fun, who all deferred most of their salaries. Dull stuff, though.