Psychic. Coven, #11.5

This gift doesn't belong to you. After being struck with a quick glimpse of the future, Kathy feels excited that her powers are growing. But as the visions begin to pick up in frequency and completely debilitate her to the point of physical exhaustion, she knows that something is seriously wrong. Seeing the way that this new power is nearly killing her sister, Samantha discovers that the new power isn't a growth in Kathy's magical abilities, but rather a power that was given to Kathy by a psychic on the run.
When Samantha tracks down that psychic, she convinces her to help Kathy, on one condition: Samantha must first help the psychic. With no other choice, Samantha is left to help the psychic before she can help alleviate the pain in her sister. And her only hope is that she can trust the psychic to make good on her word. Psychic is a short story in the Coven series, which is part of the Art of Magic universe, containing the Lost By Magic and the Under the Moon series.