1920 - Blaenau Ffestiniog, Wales: Tessa Wiggins's "madness" is provoked by the adopted spirit of a two-thousand-year-old Druid priestess mentoring her to be the servant of The Earth Mother. When Tessa defies treatment, her lover asks a childhood friend, Sherlock Holmes, to intervene. But despite everyone's best intentions, Tessa finds herself in Hellingford Asylum, where she is driven toward her final breaking point on All-Halloween.