Sherlock and John are contacted by Henry Knight (Russell Tovey), a man traumatised by the death of his father by a monstrous hound on Dartmoor years before. Investigating Dewer's Hollow, a local spot where the beast was allegedly seen, as well as the nearby Ministry of Defence testing site Baskerville, Sherlock and John uncover a conspiracy wherein one of the Baskerville scientists, Dr. Frankland (Clive Mantle), is continuing the work of H.O.U.N.D., an aborted project to create a hallucinogenic