I won't bother you with the plot, as other reviewers have given plenty of detail.
As so often in films like this, an fading American star was imported. Pat O'Brien was 58 at the time, with what one reviewer's described as a turnip face (given his Irishness, potato face seems nearer the mark.) He looks tired, though given the character is a drunken, depressed widower, that's quite appropriate.
Despite his age and lack of dynamism, O'Brien flattens three villains in a fist fight. Since one of them is played by Freddie Mills, who'd only lost the world light-heavyweight championship seven years before, that scene wasn't totally convincing (English understatement working overtime.)
The heroine is played by the lovely Lois Maxwell, 30 at the time. The character is rather silly (she interferes without knowing the facts, thereby putting O'Brien's son in danger.) The film's main problem is that the leads make a very ill-matched couple, and have zero chemistry.
This is the last of a string of low budget B movies Terence Fisher made in the '50s, all competently made without being inspired. Who would have thought that his next film, "The Curse of Frankenstein," would lead to a whole series of Hammer horrors, mainly directed by Fisher. The budgets for these were probably pretty low too, but he showed a real flair for Gothic horror, though the law of diminishing returns inevitably set in.
A couple of footnotes. The villains operate from the office of a coffee bar in which Tommy Steele performs, too much for my taste. Steele got his start in such a place. And I think this was one of the last films made in Southall studios: the area has changed an awful lot since those days.
