Back at the inn, the unthinkable happens. Sherlock Holmes—the man of pure logic—is trembling. He confesses to John that he saw the hound. For the first time, Sherlock cannot trust his own senses. This doubt leads to a breakdown of his "Mind Palace," nearly destroying his friendship with John as he lashes out in fear.
The chemical is a volatile, aerosolized fear-gas developed at Baskerville (Project H.O.U.N.D.). It targets the brain’s fear centers, turning a suggestion—a "hound"—into a vivid, lethal hallucination. Sherlock’s Mind Palace reveals that "H.O.U.N.D." was an acronym for the scientists who created the gas in the 1960s. The Confrontation at the Hollow [S2E2] The Hounds of Baskerville
This retelling of dives into the psychological fog of Dartmoor, focusing on the intersection of childhood trauma and modern chemical warfare. The Ghost in the Fog Back at the inn, the unthinkable happens
As the fog rolls in, Frankland appears. He has leaked the gas again to finish Henry off. In the chaos, a common stray dog (enhanced by the gas to look like a monster) is shot by John and Lestrade. Frankland flees but wanders into a Baskerville minefield, meeting a fiery end. The Aftermath For the first time, Sherlock cannot trust his own senses