El canario amarillo

It's 1940. Observers notice a possible signal to the German bombers up above but Sally Maitland (Anna Neagle) escapes leaving behind a dead body. She is suspected of being a Nazi sympathizer as she boards a ship to Halifax in Canada. She is approached separately by Jim Garrick (Richard Greene) and Polish officer Jan Orlock (Albert Lieven). Apparently, no one is who they appear to be or even pretend to be.

I actually like this movie while they are on the boat. It's fascinating to figure who's who and what's what in a contained location. There is a sense of claustrophobia and a lack of escape. They're trapped. When the Nazis get on board, it elevates the situation but then it goes flat. I start losing the thread of the characters. I don't know why the Nazi would just leave. They should at least execute a few of the passengers. The ship is a vastly better location for a thriller. Once the movie switches to Halifax, the sense of danger lowers. It's not a scary place even if the plot demands it to be important. The most compelling reveal is the truth about the opening scene. This is fine but the second half is a bit flat.