When several leading society figures begin acting out of character, Holmes is enlisted on an investigation that will see him team160;up with famed ghost hunter Thomas Carnacki, and the famous occultist Aleister Crowley.160;As London fills up with mindless zombies, possessed by the spirits in the air, Holmes must descend beneath the city via the new160;underground train network to combat the source.160;A brand-new original novel, detailing a thrilling new case for Sir Arthur Conan Doyle"s timeless creation.