- Appears in: 1.13 Route 666 (episode)
- Played by: Conchita Campbell
- Dispatched: When her sister Rose choses to die and keep her company forever.
- See also Ghost
When she was a child, Maggie Thompson drowned in the swimming pool at the Pierpont Hotel 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, who teaches the spells and rituals to Rose.
Maggie currently appears as an "imaginary" friend to Rose's granddaughter Tyler.
The family is now selling the hotel, and Rose, now an old woman has had a stroke and cannot do the spells anymore that restrain Maggie, and she starts killing people associated with the sale. Finally, fearing she will be left alone, Maggie lures Tyler to the pool and tries to drown her. Sam rescues Tyler, but Rose gives her life to appease Maggie, and keep her company.