It was first discovered by Benjamin Locke in 1775, during the Revolutionary War. A small army hiding in the Drowning Cave had an encounter with the Black Door, during which Harm Timmerman was possessed by a demon. Other demons were unable to find hosts, however, and fell dead, turning into Whispering Iron.
- ↑ Locke & Key: Clockworks #3, "The Tamers of the Tempest". December 14, 2012
- ↑ Locke & Key: Clockworks #1, "The Locksmith's Son". July 20, 2011