What is the conclusion of the mystery?
In Sir Arthur Conan Doyle's The Adventure of the Speckled Band, his most famous character- Sherlock Holmes- saves the life of a young woman. Helen Stoner lives with her stepfather in the country, in a great house where her sister died some years previous. Miss Stoner fears for her life, as the circumstances which preceded her sister's death seem to be repeating themselves. Before her demise, her sister was newly engaged, like Helen is now. Helen has also been hearing strange noises at night, just as her sister spoke of the night she died. In the middle of the night, Helen was so terrified by the sounds that she fled her home and came to London to seek the help of Mr. Holmes.
Sherlock Holmes and his assistant, Dr. John Watson, agree to travel to Miss Stoner's home to investigate the unfurling mystery and try to save her life. Her stepfather, Dr. Grimesby Roylott, is an eccentric man who keeps a variety of exotic animals as pets. At night, he lets a baboon run wild on the estate. Included among his exotic pets is a kind of snake called a swamp adder.
Mr. Holmes discovers that Dr. Roylott has trained his pet swamp adder to come to him at the sound of a whistle. Late at night, he has been putting the snake into Helen's bedroom by means of a grate in the wall, where it is supposed to bite Helen! Dr. Roylott used this very same method to murder Helen's sister by snakebite, as he was afraid that if she married, he would lose the fortune left to her by her dead mother. Mr. Holmes and Dr. Watson decide to stay in Helen's bedroom for the night, and when Dr. Roylott releases the snake, Holmes whacks it with his cane, sending it back through the grate. The snake is angry at having been attacked, and bites Dr. Roylott, who perishes from the venom. Helen survives the incident with both her life and fortune in tact.