Inner Demons (Book Eight of the Silver Society)

Something is very wrong in Salem. It soon becomes clear to the members of the Silver Society that the impossible has happened and one of their own is possessed. Aideen takes control of the Silver Society, but quickly finds that facing off against an evil entity in the body of someone she cares about isn't as easy as she hoped.

Meanwhile, Jade's past comes back to haunt her as Salem faces a threat it hasn't seen in twenty years... Devil Worshippers.