Marked

When Lucky is called in to investigate a spectral disturbance at the all-girls school she attended as a child, she isn't surprised. She herself had had a terrifying confrontation with the troubled spirits of two girls who died in the attic room. But when Lucky goes up to the attic, she discovers that the vicious little girls are the least of the problem--a demon has been released into this world, a creature of such malevolence that even the spirits of the two girls are afraid. When the demon demands that Kayla be handed over to him, Lucky realizes that this case will be like no other she has ever experienced.

For one thing, it seems that her chatty, snarky spirit companion is not what she has always seemed to be...