Island in the Sky (1938)

Director: Herbert I Leeds
Starring: Gloria Stuart, Michael Whalen, Paul Kelly
Synopsis:
The assistant and prospective bride of the district attorney goes out on her own to try to prove the innocence of a man convicted of murder.
Impressions:
You really shouldn't marathon a bunch of these old mysteries or they start to blend together. This one stands out slightly in that it takes place at the point in the character arc where the UST between the "detective" and his assistant is being resolved and its actually the assistant who's doing most of the work. That novelty and some interesting twists along the way make this worth considering, but this is by no means exceptional.
50/50