S4·E9 The Night of Fire and Brimstone

West and Gordon are called to the deserted mining town of Brimstone by a Professor Colecrest who has made a discovery of great importance. However, before they get to Brimstone, the Professor is captured by a gang of men also seeking his discovery. The professor, seriously injured in a fall, holds the key to the mystery, and Jim and Artie struggle to keep him alive until they can uncover the true root of the mystery.