Paris (Dylan O’Brien, who can also be seen doing an ace Dan Aykroyd impression in “Saturday Night”) is haunted by the death of his mother, who had some sort of seizure while driving Paris, plunging them off a bridge. His survivor’s guilt haunts his body language, conveyed well by O’Brien as a man who is trying to figure out exactly what happened to his mom, even going as far as confronting her doctor in a parking lot to get answers. But he also suspects maybe there’s more to the event, something darker under the surface of Caddo Lake.