The Scarlet Claw

The Scarlet Claw is a 1944 Sherlock Holmes movie directed by Roy William Neill, starring Basil Rathbone and Nigel Bruce. It is the eighth film of the RathboneBruce series. David Stuart Davies notes on the films DVD audio commentary that its generally considered by critics and fans of the series to be the best of the twelve Holmes films made by Universal.

Holmes and Watson arrive at the village and discover that the inhabitants are all convinced that the murder is the work of the legendary monster of La Mort Rouge, which roams the marshes around the village. The monster is even later seen by Dr. Watson, who describes it as a ball of fire spitting flames in each direction.Holmes, however, is skeptical, and recognizes Lady Penrose as Lillian Gentry, a former actress, who was involved in a famous murder case several years before when actor Alistair Ramson killed another actor in a jealous rage over her. Ramson was believed to have been killed in a prison escape two years before, but now Holmes believes that Ramson a master of disguise is living in the village, having created a new identity, perhaps several, for himself. ........

Source: Wikipedia