This film, although not as well-crafted as THE THIRD MAN or THE MAN BETWEEN, is definitely in their league; it's a taut, post-war mystery in which a European city (in this case, Venice) is one of the most important characters. The main human character, Edward Mercer (Richard Todd), is a Hitchcockian protagonist: a man trying to prove his innocence in ever more dire circumstances.
The plot does get convoluted at times, but director Ralph Thomas always keeps your eyes interested with wonderful location shots. The cast is solid, and Sid James is given a rare dramatic role. The ending, also with Hitchcockian overtones, is thrilling and a fine bit of camera work and direction. (May I recommend that after you finish the film, go back and watch the first few minutes again. You'll see how cleverly the motifs of the film are tied together.)
The plot does get convoluted at times, but director Ralph Thomas always keeps your eyes interested with wonderful location shots. The cast is solid, and Sid James is given a rare dramatic role. The ending, also with Hitchcockian overtones, is thrilling and a fine bit of camera work and direction. (May I recommend that after you finish the film, go back and watch the first few minutes again. You'll see how cleverly the motifs of the film are tied together.)