Helen Stoner goes to Sherlock Holmes and Dr. Watson. She is afraid that her stepfather, Dr. Grimesby Roylott, may be trying to kill her. Helen’s sister died mysteriously two years earlier, right before her own wedding. Her last words, which Helen never managed to decipher were "The speckled band". Dr. Roylott’s best friends are a band of gypsies. He also owns two dangerous animals, a cheetah and a baboon, as pets. He simply scares people, and everyone avoids him. But the great Sherlock Holmes cannot be scared away this easily, so he agrees to take the case and to protect Helen.Who is threatening Helen’s life and who murdered her sister? Will Sherlock Holmes manage to find the murderer and protect the frightened woman at the same time? Will he be able to decipher Helen’s sister's last words? Why is Dr. Roylott such an evil man and what is his plan?You can find all the answers in one of the best of Sir Conan Doyle’s stories about Sherlock Holmes – "The Adventure of the Speckled Band".