The Scarlet Claw is a 1944 Sherlock Holmes film directed by Roy William Neill and starring Basil Rathbone and Nigel Bruce. It is the eighth film of the Rathbone/Bruce series. David Stuart Davies notes on the film’s DVD audio commentary that it’s generally considered by critics and fans of the series to be the best of the twelve Holmes films made by Universal.
Holmes and Watson are in Canada attending a conference on the occult, when Lord Penrose receives a message that his wife Lady Penrose has been murdered in the small village of La Mort Rouge. Holmes and Watson are about to return to England when Holmes receives a telegram from Lady Penrose, issued before her death, asking for help as she fears for her life. Holmes decides to investigate her death.
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.
Holmes then turns his attention to Judge Brisson, another inhabitant of the village with a connection to the case, as he passed sentence on Ramson. Despite Holmes’ warnings, Brisson is murdered. Holmes tracks Ramson down to his hideout and discovers there is a third person that Ramson is preparing to kill. While Ramson is holding Holmes at gunpoint, Watson blunders in and Ramson escapes, albeit before Holmes can learn who Ramson’s final target is.
Holmes learns that the third victim is to be Journet, the local inn-keeper, formerly a prison guard. However Journet has gone into hiding. Ramson then kills Marie, Journet’s daughter, for not revealing her father’s hideout. Holmes finds Journet and convinces him to spring a trap for the murderer.
Holmes and Watson announce that they are returning to England, and Journet comes out of hiding and lets it be known that he will be going to a church across the marsh to offer a prayer for Marie. Ramson attacks Journet out in the marsh, only to find that it is Holmes disguised as Journet. The two men struggle, but Ramson escapes only to be killed by Journet with his own weapon, a five-pronged garden weeder.