After the impressive Take Shelter, writer-director Jeff Nichols takes on the sort of swampy southern gothic that David Gordon Green handled so masterfully in Undertow (2004). An unhappy 14-year-old (Tye Sheridan) in backwater Arkansas, exploring a wooded island on the Mississippi with his pal, discovers a wanted man (Matthew McConaughey) hiding out there and becomes his friend and accomplice, learning that he committed murder to protect his beloved but cheatin’ girlfriend (Reese Witherspoon). Nichols takes his time with the story, dwelling on how the boy is shaped by the killer’s tragic sense of romance, yet the suspense holds. Sam Shepard, Michael Shannon, and—get this—Joe Don Baker contribute strong supporting performances, and McConaughey continues on his unlikely but fascinating career arc from drawling golden boy to Mitchum-style loser.