A homeless man is wandering around an Italian port city with a pistol. He is looking to sell it to get himself money for passage on a boat leaving at midnight. The junk man won't take the gun, and the junk man's friend who deals in black market goods is only willing to offer the homeless man a pittance. The homeless man gets riled up and nearly pulls the trigger on the low-balling cheat. He restrains himself, though, and sticks the pistol back in his pocket before going on his way.
The homeless man, whose name we never learn, is played by Paul Muni (Scarface, I Am a Fugitive from a Chain Gang). For a large chunk of 1952's Stranger on the Prowl, Muni's performance as this homeless man is centered on his face. The character does speak -- with an American accent that sounds out of place amidst all the Italians in the cast -- but all of the character's anguish, fatigue, and anger is constantly being communicated by Muni's extremely expressive eyes. (And, even though his character is unkempt and unshaven, it has to be said that Muni looks awfully good for a fellow in his mid-50s.) One could get the sense that maybe the character is trying to divert energy away from his body. That might seem like a bit of a logical leap, but there are a few isolated moments where Muni's character unleashes his considerable physical strength -- and mostly the results are not good.
The first big turning point of the story arrives when the famished homeless man walks into a cheese shop. He grabs a wheel of cheese from the window and just starts eating. The woman who owns the shop begins yelling at him. He puts his arm around her head to stop her from screaming and ends up accidentally breaking her neck. A woman at a shop across the way sees the murder and starts yelling for the police. As the homeless man flees, a young boy called Giacomo (Vittorio Manunta), who has just shoplifted some milk from the cheese shop mistakenly believes the cops are being called on him. Both Giacomo and the homeless man end up fleeing and hiding together, with Muni's character never taking a moment to set the kid straight about who the real fugitive is.
Even though the film was directed by an American, the blacklisted Joseph Losey (The Servant), the Italian setting obviously inspired Losey to emulate the neorealist style, with a lot of location shooting and a selection of main characters who are all suffering in abject poverty. It's not a completely successful example of the form. Certain moments drift too far into over-the-top melodrama, while other scenes are so "realistic" that they're just dull.
The final thirty minutes of the film, where Muni's character and Giacomo hole up in the apartment of a young woman named Angela (Joan Lorring), sees the movie shift stylistically more toward film noir. It's a good move, giving the film greater dramatic immediacy. Muni's character has been shot in the arm. The police have surrounded the neighborhood and are beginning to systematically check all the buildings. Muni's character is given a chance in this final passage to show his best and worst sides, eloquently expressing his thwarted desires to Giacomo but then lashing out violently at Angela when she tries to escape.
The film seems to side with Muni's character, seeing some justification in his pain and anger. To the film's credit, it does not shy away from showing the ugliness that can come when these feelings are mismanaged. And to his credit, Muni does not allow his character to be turned into a mere monster. His "Stranger" has simple motivations but he is shown to have a complex intellect and emotions. Therefore, even though the plot is undercooked and thematically the film is a little muddled, Stranger on the Prowl stands as a better-than-decent acting showcase for Paul Muni.