Nan was born with this ability. She first displayed this power when she read Madison's mind about how she killed the director using Telekinesis. She also read Delphine's mind and commented on how she is annoying her. Zoe's mind about how she stressing over Kyle. She also read Queenie's mind about how she is a virgin. She also read Luke's mind about how Joan Ramsey killed her husband.
When Fiona was receiving chemotherapy, she could read the thoughts of the cancer patients in the room and commented on how she could never do that before. The Demon often enjoyed reading a person's mind to see their secrets, such as Sister Jude's alcoholic past and the "murder" she committed to its own amusement.