Generation L: Guardian WIT book 1

Marna Farlow's life is about to change. A phone call in the middle of the night holds a call to action to save her twin sister's children from an unknown threat. Unfortunately, it also relates to the fact that she could not save her sister. "Its too late for us, but you must save the children!" Amanda cries.
Marna and her husband Jeff answer the call. However, when they arrive at the small farm, there is no life within the walls of the traditional farmhouse. They find the body of Amanda, her...