Nightstruck / Black, Jenna

Something evil tricks Becket into opening a portal to another realm from which comes a darkness that transforms Philadelphia into something ghastly, but only at night. While some citizens lock themselves indoors at night, others run wild. Now Becket, the daughter of the police commissioner, must find a way to survive and undo what she has done.

"Becket is an ordinary teenage girl, wrestling with the upheaval of her parents' divorce. A studious high school senior, her biggest problems to date have been choosing which colleges to apply to, living up to her parents' ambitious expectations for her, and fighting her secret crush on her best friend's boyfriend. But that all changes on the night she tries to save an innocent life and everything goes horribly wrong"--OCLC.