Then things change. A friendly police officer informs Dwight that the man serving time for murdering Dwight's father is being released from prison. That sets in motion an escalating series of increasingly violent events that draws heat not only on Dwight but also his (innocent) sister. Even though Dwight is our nominal "hero", he does a lot of thoroughly non-heroic things, screws up repeatedly and ultimately makes some discoveries that suggest his quest for justice (or whatever it is) may actually be wrong-headed. The movie's also not about steely super soldiers. There's a very sensible scene in the film where an injured person tries to fix a wound on their lonesome, Rambo style, only to fail miserably and resort (sensibly!) to the E.R. You'd never see Stallone do that!
Blue Ruin is very quiet for this sort of film, with several scenes of real tension that reminded me of the recently concluded True Detective series. There are a few eyebrow-raising moments (I'm either impressed or unnerved at how many people in this film don't seem particularly gob-smacked by murder) but overall it's a nice, tense piece of work. I liked it!