An old family document says that everyone who l ivesat Baskerville Hall is in danger from a terrifying animal which lives on Dartmoor. When Sir Charles Baskerville dies in a mysterious way, his nephew, the young Sir Henry Baskerville, comes to live on Dartmoor. Is he in danger too? Is there really a dangerous animal on the moor, or did someone murder Sir Charles? Sherlock Holmes, the world-famous detective, is the only person who can solve the case. Or can he? Even Holmes is worried.