Officer Chris McCullers was gravely injured in a shootout and now works on 911-dispatch. Resentful that her career has ended up here, Chris receives a call from a scared kid and dismisses it as a prank. The next day, she learns that the call was all too real: there’s been a murder. Chris obsesses over the case, listening to the call repeatedly until she has a theory of her own. Seeking redemption and justice, she takes matters into her own hands and puts her life on the line.