If you’re looking to be mystified for most of a story, The Vicious Circle (1957) might fill the niche. A surgeon picks up a woman from London Airport as a favor to a friend, only to discover her body in his flat the next day, the reporter who gave him a ride to the airport doesn’t exist, the police seem to know more than they should, yet keep letting him slip through their fingers, and his friend didn’t make the call.
Laboring to keep his fiancee happy while he evades the police and tries to resolve the mystery, he keeps digging up more and more mysteries: why does his colleague, Kimber, seem to know his fiancee, yet they both vigorously deny it? What about his patient who lies about her visit with him? Who’s the guy who’s willing to trade a photo that proves the reporter exists for a very particular box of matches?
You won’t guess what’s going on, but the reveal is snappily done. Plans don’t go according to plan,which is quite pleasant, and the acting is more than competent in the British mode. In the end, it’s one of those movies you won’t remember, but you won’t regret watching.