[s2e2] The Hounds Of Baskerville Direct

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

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. [S2E2] The Hounds of Baskerville

Determined to find a rational explanation, Sherlock realizes the "hound" isn't a physical creature, but a . He suspects a chemical agent and tests John by trapping him in a Baskerville lab, triggering a terrifying "encounter" with the beast through the base's sirens and lights. The Revelation of the Fog As the fog rolls in, Frankland appears