After years of work, Chicago readies for the opening of the 1893 World's Fair. As engineers race to put the finishing touches on the fairgrounds -- a 600-acre modern marvel meant to memorialize the 400th anniversary of Christopher Columbus' discovery of the New World -- an evil con man prepares a personal welcoming campaign. Herman Webster Mudgett, better known as charismatic doctor and infamous killer H.H. Holmes, lures visitors to his own playground, a blocklong structure later nicknamed "The Murder Castle." Under the guise of a hotel, the building is designed to trap Holmes' prey, with stairways to nowhere, doors that open onto brick walls, and sealed "death rooms." Before long, the doctor makes victims mysteriously vanish, never to be seen again.