'Offbeat' (1961) – Cliff Owen.

Director Cliff Owen's brisk 60s crime caper demonstratively remains an exciting, palm-sweatingly dynamic underworld thriller exposing the inherent risks of Scotland Yard's cavalier methodology to thwart the increasingly audacious criminal elements lurking within the UK's labyrinthine metropolis. Steve Ross (William Sylvester) is an ice-pick cool undercover agent, and after successfully infiltrating an established firm, Steve very soon finds himself dangerously embroiled in an especially audacious jewel heist which ultimately prompts him to realign his allegiances to his own financial, if not moral advantage! The robbery itself is beautifully conceived, energetically orchestrated by gifted film-maker Owen, in fact the film's stylistic influence on contemporary Brit-crime thrillers is quite obvious. 'Offbeat' has an unusually robust text, winningly vivid performances from a talented cast, including another luminous turn from the always delightful Mia Zetterling, and maestro Ken Jones's exemplary jazz score provides an exhilarating backbeat to the palpably tense, increasingly white-hot intensity of the gang's subterranean larceny! 'Offbeat' is a hard-hitting, finely-honed Brit-crime classic that forcefully maintains its sinewy grip right until its legitimately thrilling climax. Fans of cult British cinema might care to know that journeyman director Cliff Owen also directed the amiable farce 'No Sex Please We're British!' (1973)