In 1878, they kept Tessa Gray prisoner there while they taught her how to Change in preparation to marry the Magister. With them were clockwork servants, including the maidservant Miranda and the unnamed coachman.
One cellar of the house served as a slaughterhouse for the murdered humans whose bodies were used to make the first of Mortmain's automaton army. In the cellar were rows of long wooden tables, where the bodies of their dissected victims would be turned into automatons, a center table containing the piles of bloodied knives and mechanical devices, and a large drain in the middle of the floor.
The Shadowhunters of the London Institute were first led there while following through an investigation of the double ouroboros symbol of the Pandemonium Club. When they found and rescued Tessa from her bedroom, where she was held the majority of the time, the encounter led to a fight between the Dark Sisters and the Shadowhunters. After the battle, the house's furniture was sent to the Silent City to be searched and examined by the Silent Brothers.
Later, Will Herondale and Jem Carstairs returned to the house to further investigate and found the automaton Miranda, who was seemingly broken and "survived" only long enough to pass on a warning to the Nephilim from the Magister.