Samuel Hunter, Caitlin O'Sullivan, and Granville Woods battle supernatural forces in late 1800s Boston. Upset over Samuel working with Tesla, Caitlin quits and hurries home only to face her mother's fury over her working for the Boston Metaphysical Society. Granville approaches an old foe for help, and Samuel is called away to deal with a haunting in one of the Great Houses. But is something else going on?