Every Sherlock episode RANKED

10. The Hounds of Baskerville

A young man called Henry Knight (Russell Tovey) contacts John and Sherlock to investigate the death of his father, who was killed by a monstrous hound on Dartmoor a few years previously. The pair uncover a conspiracy involving an organisation known as H.O.U.N.D and an aborted project to create a hallucinogenic gas for military use, coming face to face with a murderous scientist and a very normal dog. Oh, and at the very end Mycroft releases Jim Moriarty from prison. That's wise...