While camping out, a Wyoming sheep rancher and his son are accidentally sprayed with a secret poison. The boy dies while the military covers up its mistake, enlisting civilian personnel in the cover-up. But will the father find out, and if so, what will he do.
It's important to keep in mind that the screenplay is based on a true 1968 occurrence. The Pentagon covered up poisonous contamination of several thousand sheep in Utah, and only admitted it after overwhelming evidence. I assume they were wary of being seen experimenting with poisonous chemical at a time when the Vietnam War was going badly. The movie itself is very methodical. The first part dealing with the cover-up shows how deception is spread among medical and military professionals. Surprisingly, however, no higher justifications such as national security are cited. It's more like an embarrassment than a security breach.
Anyway, Scott really low-keys it throughout, being good-citizen cooperative even as he's fed one lie after another about his son. Even after he finds out the truth, his rage is more intense than histrionic. I guess I was expecting him to explode in the scary way that only he can. Apparently, the actor wasn't happy with his performance (TCM), blaming it on his divided roles as both director and lead performer.
All in all, the movie's like a slow fuse being lit until it finally goes off. Just how sane Logan (Scott) is during those climactic moments is, of course, anybody's guess. Considering what's happened to him, his actions are understandable, if not excusable (innocents die). At the same time, the lessons are, if anything, more relevant now than then, especially with the rise of our national security state and its mass surveillance program.
(In passing—this is one of the few films I've seen to actually portray death throes as the person expires. Kudoes to Scott for including such a disturbing detail that traditional Hollywood avoided like the plague. More of that and audiences might take a different view of movie violence.)