If you hadn't guessed from the title, this one is a bit weird. Sam Elliott is Calvin Barr, a World War II veteran living out the quiet later days of his life in a small town. We see flashbacks to his mission to kill Hitler during the Second World War, and learn that he's still surprisingly proficient at self defense despite his age. As improbable as this all was, it was moving along well largely due to Elliott (as other critics have noted). But then they tried to recruit him to kill Bigfoot ... which I could have dealt with until they mentioned the backup plan if he wouldn't come, which was to nuke a large portion of Canada. My giggling kind of got in the way of my suspension of disbelief, which was unfortunate: I'd got through them killing off Hitler okay.
As crazy as it is, a well written dialogue and a very good performance from Elliott make this fairly watchable.