Influenced by Sir Arthur Conan Doyle's The Final Problem and The Adventure of the Empty House, The Woman in Green (set in the then-present day setting of 1940s London) tells of Sherlock Holmes's final confrontation with Professor Moriarty and a seductive female hypnotist.
When Moriarty hatches another scheme, Holmes and Dr John Watson are once again called into action. The scheme is removing women's forefingers. Sir George Fenwick, after a romantic night alone with his girlfriend Lydia Marlowe is hypnotized into believing that he is responsible for removing the forefingers. He is certain that he has done it after he finds one in his pocket. His daughter comes to Holmes and Watson (she doesn't know that a man is following her, which Holmes discovers when he sees a taxi following her. However, the person inside sees him and parks at an empty house.), and tells them that she found her father putting a forefinger under a pile of soil.
Fenwick is then found dead. Holmes believes that Moriarty is responsible for the crimes. Watson is then called to help a woman who fell over while feeding her pet bird. He exits mumbling to himself that there should be a law against fat people keeping birds. Minutes later, Moriarty appears and explains that he called Watson so he could talk to Holmes and make him believe he is holding Watson hostage so he'll let him stay. He then leans one of the chairs back. Holmes sees an open window, which is directly across the window of the empty house and the chair. He does not sit in the chair. When Moriarty leaves, Watson arrives. Holmes explains what Moriarty did and tells Watson to explore the empty house. Inside the empty house, Watson sees a sniper shoot Holmes. Holmes then appears and explains that he put a statue there because he knew as soon as he sat there, that would be the end of Sherlock Holmes. Gregson takes the sniper-an hypnotized ex-soldier- away, but he is killed a little while later on Holmes doorstep! Holmes, who now has a plan, makes friends with Lydia. She takes him to her house, where he is hypnotized. Moriarty, who is helping Lydia, tells him to jump off the building. Watson and the police then appear and grab the criminals. Holmes then reveals he wasn't really hypnotized. Moriarty then escapes from the hold of a policeman and jumps from the top of Lydia's house to another building. However, he hangs onto a pipe which becomes loose from the building, causing Moriarty to fall to his death. Holmes and Watson quietly celebrate their victory against Moriarty.
- Basil Rathbone as Sherlock Holmes
- Nigel Bruce as Dr John Watson
- Hilary Brooke as Lydia Marlowe
- Henry Daniell as Professor Moriarty
- Paul Cavanagh as Sir George Fenwick
- Matthew Boulton as Insp. Tobias Gregson
- Eve Amber as Maude Fenwick
- Frederick Worlock as Dr Onslow
- Tom Bryson as Corporal Williams
- Sally Shepherd as Crandon
- Mary Gordon as Mrs Hudson
- Two stories in particular are the influences of this film, The Final Problem and The Empty House;
- Like The Final Problem, Moriarty delivers a false message to Dr Watson of an injured woman in order to lead him away from Holmes, so that Moriarty and Holmes can speak privately. In the same scene, an accurate recreation of Holmes and Moriarty's first confrontation in Baker Street occurs. As with The Final Problem, the story ends with Moriarty falling to his death – though here he falls from the top of a building rather than a waterfall. Moriarty met his end in a similar way twice before, in the climaxes of The Adventures of Sherlock Holmes (1939) and Sherlock Holmes and the Secret Weapon (1943).
- Like The Empty House, Sherlock Holmes catches an assassin hoping to kill him by placing a false silhouette in the light of his window at his room in Baker Street, only to sneak upon the assassin. In this version, the silhouette is from a bust of Julius Caeser, who has a facial resemblance to Holmes: "Incidentally, you will have noticed that through the ages, prominent men have prominent noses".
- The assisting Inspector in this film is Inspector Gregson, who appeared alongside Inspector Lestrade in A Study in Scarlet.
- Holmes is shown to be emotionally involved in this case, feeling repulsed at the murder of women. Though Holmes prefers to be a thinking machine, he was known to become emotionally compromised in certain Conan Doyle stories and actually enraged with his antagonists, such as in "The Five Orange Pips" and "A Case of Identity".
- Like with Sherlock Holmes and the Secret Weapon, the final credits misspell Moriarty's name as "Moriarity".
- Moriarty intends to fake Holmes' suicide, a scheme which was also used in the Sherlock episode "The Reichenbach Fall".
- Temptress of Pleasure – or Mistress of Murder?
- From Her Lips – Poison That Bred Murder!