“A Single Shot” is an impressive detour in the career of Sam Rockwell. After his entertaining but routine turn in last summer’s “The Way, Way Back,” Rockwell returns to his dark side in this tense, unflinching thriller. Similar in a few ways to Sam Raimi’s “A Simple Plan,” “A Single Shot” has a spare quality that keeps it unsettling, while its coldly violent attitude encourages a steady pace. And there’s Rockwell, delivering a fantastic performance as a simple man in way over his head, reining in his flashier, boogie fever instincts, allowing director David M. Rosenthal’s gloomy mood of impending doom to carry the viewing experience. Read the rest at Blu-ray.com