Dr. Mudgett graduated from the University of Michigan Medical School in 1884, where he amused himself by stealing cadavers from the lab, and concocting elaborate insurance schemes.

By 1888, Mudgett was working as a chemist in a drugstore in Chicago under the name H.H. Holmes. His employer (a woman) mysteriously disappeared in 1890, leaving him in control of a flourishing business. Above the drugstore was a flat which Homes shared with a married couple, Icilius and Julia Conner; he was a jeweler, while Julia worked as Holmes’s secretary. Julia and her daughter were just two of the twenty-seven victims Holmes bragged of having murdered. Across the road was a vacant lot, which Holmes purchased as the site for his hotel, named appropriately "Holmes’s Castle."

The hotel, which was completed in 1891, had been built by several different crews of contractors, hired by Holmes to prevent any one person from knowing all of the features of his killing jar. Inside, the hotel was surreal. There were rooms without doors, doors that opened onto brick walls, an elevator shaft with no elevator and an elevator with no shaft. There were also trapdoors, secret passages and hidden stairways.

All the guestrooms were equipped with peepholes so that Holmes could spy on female guests undressing. After seducing and chloroforming a victim, she would be slipped into a greased chute – there was one on each floor -- which led to the building’s basement. Once in the basement with his victim, a whole range of amusements awaited him. One of Holmes’s favorite activities was to place his unconscious victim in a sealed room with a glass ceiling. As he admitted in his memoirs, he enjoyed watching the woman wake up and realize she was trapped and seeing her scream and claw the walls. Then, when her terror was at its height, poison gas would be pumped into the chamber as Holmes sat back and enjoyed her death throes.

But the gas chamber room (which Holmes referred to as "the vault") was only the beginning. There was an asbestos-lined room with a large gas jet in one wall for incinerating luckless women; there was a dissection room, which contained numerous instruments of surgery and torture, and a third room which held a rack. In addition, there were complete facilities for disposing of embarrassing evidence: an oven for cremation, large vats of acid, and, of course, the tried and true lime pit.

In 1894, Holmes was arrested for insurance fraud - the police searched the hotel, and the house of horrors was revealed, including the skeletons of several women. He confessed to twenty-seven killings and detailed them in his memoirs. He was hanged in Moyamensing Prison in Philadelphia on May 7, 1896. His castle, he wrote in his memoirs, was designed "...for the pleasure of killing my fellow beings, to hear their cries for mercy and pleas to be allowed even sufficient time to pray…"