Frank Grimm is a retired detective who breaks into his neighbors' homes searching for clues to find the man who murdered his daughter. What was once an unrelenting obsession in solving a crime has turned into something else — Frank breaking and entering, vicariously living through their lives, searching for a connection to anything.

One day he finds something waiting for him — a letter from a teenage girl who knows what he's doing. It also says one other thing:

"Help, my father is raping me. Please kill him."

Frank must decide how far he'll go outside the law to save a child from a monster.

But his former ally, detective Mallory Black, is tracking his every move -- she believes he escaped justice once, and she is not going to let it happen again.

Detective and ex-detective find themselves on a collision course as their lives are torn apart by their obsessions for delivering justice, no matter the costs.