When she was a child, Maggie Thompson drowned in the swimming pool at the Pierpont Inn, which is owned by her family in Cornwall, Connecticut. She haunted the hotel as a vengeful spirit, kept in control with voodoo from Marie, the nanny of Maggie's surviving sister Rose Thompson, who teaches the spells and rituals to Rose.
After Rose Thompson suffers a stroke, and can no longer perform the hoodoo rituals needed to keep Maggie in line. Maggie begins to appear as an "imaginary" friend to Rose's granddaughter Tyler Thompson. As well as killing associated with the impending sale of the hotel. When she fears that she will be left alone, Maggie lures Tyler to the pool and tries to drown her, however Sam rescues Tyler, but in the end Rose gives her life to appease Maggie, and keep her company.