In the late 19th century, Dr. John Watson and the brilliant detective Sherlock Holmes are thrust into one of their most sinister investigations yet. When Mrs. Mary West approaches them with a desperate plea to find her missing husband, William, the case leads them across the Atlantic to the bustling streets of Chicago during the 1893 World’s Fair. Amid the dazzling splendor of the "White City" lies a dark underbelly of deceit, danger, and death.

As they dig deeper, Holmes and Watson uncover a web of disappearances centered around a mysterious hotel known as "The Castle," owned by the charming yet enigmatic H.H. Holmes. Beneath its façade of hospitality lies a labyrinth of horrors: trapdoors, secret passages, and chambers of death. What begins as a search for a missing man transforms into a confrontation with a master manipulator whose crimes blur the line between genius and monstrosity.

Through encounters with architects, journalists, and Pinkerton agents, Holmes methodically unravels the truth behind Holmes’ gruesome empire. But when the case becomes personal, and the danger more immediate, the detective duo must rely on their wits and courage to survive.

This tale of intrigue, deception, and moral reckoning pits Sherlock Holmes against one of history’s most infamous serial killers in a battle of intellects—and a race against time to bring justice to the countless lives lost in the shadows of the White City.