This crime B feature is distinguished by the b&w footage shot in the historic Pool of London, which stretches east from Tower Bridge through the capital's (former) dockland. Now the film survives as a photographic document of a district which has mostly been swept away. Everything else feels secondary to the location.
This is social realism and it allows the director Basil Dearden to address contemporary issues, particularly the subject of race. And the film is significant as the debut of the leading black actor in British films over the next decade, Earl Cameron.
His will they/won't they flirtation with Susan Shaw is way ahead of anything in a fifties Hollywood film, and allows the character to reflect on his status as a social outsider. Cameron plays a sailor with two days shore leave. The film dwells on his friendship with a shipmate (Bonar Colleanno) who gets sucked into a diamond heist.
Which sets in motion a police investigation. The crime is really a subplot. The relationships matter more, but Dearden stages the heist and chase sequences with expertise and flair. It's a minor, low budget production with no stars, but an interesting curiosity which features many resonant performances in minor roles.