During WWII several murders occur at a convalescent home where Dr. Watson has volunteered his services. He summons Holmes for help and the master detective proceeds to solve the crime from a long list of suspects including the owners of the home, the staff and the patients recovering there.
| Actor | Role |
|---|---|
 Basil RathboneSherlock Holmes | Sherlock Holmes |
 Nigel BruceDoctor Watson | Doctor Watson |
 Dennis HoeyInspector Lestrade | Inspector Lestrade |
 Hillary BrookeSally Musgrave | Sally Musgrave |
 Mary GordonMrs. Hudson | Mrs. Hudson |
 Halliwell HobbesAlfred Brunton, the butler | Alfred Brunton, the butler |
 Milburn StoneCapt. Pat Vickery | Capt. Pat Vickery |
 Minna PhillipsMrs. Howells | Mrs. Howells |
 Arthur MargetsonDr. Bob Sexton | Dr. Bob Sexton |
 Gavin MuirPhillip Musgrave | Phillip Musgrave |
 Frederick WorlockGeoffrey Musgrave | Geoffrey Musgrave |
 Norma VardenGracie the Barmaid | Gracie the Barmaid |
 Peter LawfordYoung Sailor at Bar | Young Sailor at Bar |
| HHeather WildeNot listed | Not listed |
 Olaf HyttenCaptain MacIntosh | Captain MacIntosh |
| EEric SnowdenSailor Playing Piano | Sailor Playing Piano |