Edna May Oliver’s depiction of the precise and unsentimental schoolteacher "Miss Withers" evokes Miss Marple. The appearance of some fish in the aquarium where the police find the body of the generally unpopular "Parker" is unsettling, though. It's revealed that his wife (Mae Clarke) is having an affair with a man (Donald Cook), and they were both there when he died. This seems like an easy case for "Insp. Piper" (James Gleason) at first glance, but his encounter with the keen intellect of the reserved "Withers" quickly changes his mind. Despite his initial polite dismissal, he comes to see that she’s a remarkably perceptive helper as things become more complicated than they initially appeared. The plot itself feels very much like an Agatha Christie story—full of misleading clues and a victim who was widely disliked. Quick direction and some clever exchanges between the detectives keep the film flowing well. Will they succeed in uncovering the truth? It's predictable, but not really essential – this is about the personalities involved, and Oliver and Gleason have good chemistry as they argue, bicker, and... ultimately solve things together for seventy minutes.

Source on TMDB