Jackson Briggs, a professional soldier, is doing his utmost to return to the line, but due to a head injury he keeps getting constant denials. When one of his fellow service members dies, Briggs is given a mission: from his base in Washington state to attend the funeral of Nogales's Arizonan battle buddy—the late nervous Belgian Shepherd Lulu—who bears a full spectrum of post-traumatic disorders. Because the dog is afraid of flying, they will have to travel by car along the Pacific Coast, and this trip will not be Briggs's easiest assignment.