A marksman living in exile is coaxed back into action after learning of a plot to kill the President. Ultimately double-crossed and framed for the attempt, he goes on the run to find the real killer and the reason he was set up.
Bob Lee Swagger (Mark Wahlberg), a retired USMC Force Recon Gunnery Sergeant and Scout Sniper, is one of the few snipers in the world whose marksmanship abilities allow him to "take out a target from a mile away". He reluctantly leaves a self-imposed exile from his isolated mountain home in the Wind River Range at the request of Colonel Isaac Johnson (Danny Glover). Johnson appeals to Swagger's expertise and patriotism to help track down an assassin who plans on shooting the president from a great distance with a high powered rifle. Johnson gives him a list of three cities where the President is scheduled to visit so Swagger can determine if an attempt could be made at any of them.