[s2e2] The Hounds Of - Baskerville

Sherlock realizes the drug isn't in the sugar or the water—it’s in the of Dewer's Hollow.

They rush back to the Hollow to find Henry on the verge of suicide, driven mad by the gas. Sherlock explains the truth: Henry didn't see a monster twenty years ago; he saw in a gas mask and a "H.O.U.N.D." t-shirt, murdering Henry's father over the secret of the gas. Henry’s child-mind interpreted the mask and the red goggles as a demon dog. [S2E2] The Hounds of Baskerville

The story begins with , a man haunted by a twenty-year-old memory. As a child, he watched his father torn apart in "Dewer’s Hollow" by a monstrous, red-eyed hound. The trauma has festered into an obsession, drawing Sherlock Holmes and John Watson away from the boredom of London and into the eerie, mist-laden landscape of Dartmoor. Sherlock realizes the drug isn't in the sugar

The story closes with a chilling realization. Sherlock’s "Mind Palace" vision of in a prison cell was actually a lingering effect of the gas—a shadow of his greatest fear. As Henry finally finds peace, the episode ends with a teaser: Mycroft releasing Jim Moriarty from a holding cell, where the villain has written "SHERLOCK" all over the walls. O.U.N.D. project? Henry’s child-mind interpreted the mask and the red