Nigel Bruce’s character, “Watson,” finds himself assisting at a home for soldiers recovering from injuries, where his helper, “Sexton,” is found stabbed. Wanting to avoid involving the police and potentially upsetting the patients, he brings in “Holmes” (Basil Rathbone) to investigate. Upon arrival, Holmes learns that the house belongs to the Musgrave family, who seem to dislike each other intensely. When the older brother, “Geoffrey,” dies unexpectedly, his brother “Philip” becomes a suspect, though Holmes isn’t convinced of his guilt. The appearance of “Lestrade” offers some hope of uncovering the true killer and understanding why this family seems plagued by misfortune. It's an intricate narrative with familiar faces, along with Halliwell Hobbes in the role of the constantly-blamed butler, a group of residents who could all be guilty, and a final chess match that adds to the intrigue. My only minor issue is that Great Britain never had a monarch named Henry; otherwise, this installment finds the detective team performing admirably and concludes with a patriotic speech from Rathbone about freedom that would have certainly resonated during World War II.

Source on TMDB