Guardian. The Lost Girls, #5

Guardian is book 5 in The Lost Girls seriesKatalina Wimple's been fighting monsters since she was trapped in a dark basement as a teenager. Twenty seven years later she's still fighting them, but this time she does it to shine light into the dark basements of her foster kids. But the darkness is looking back. Katalina has to come out of retirement when her past comes back to haunt her. Disappearing friends are only the beginning of her problems.
When one of her fosters is put in danger there's nothing Katalina won't do to stop the monster out to hurt them, even if it kills her. Look for these other Lost Girls books:Book 1: The Lost GirlsBook 2: TraitorBook 3: WolfgirlBook 4: Black WidowBook 5: Guardian