Ian McCord is a young man from rural upstate New York who's bored with life and sets out seeking adventure. In search of adventure, McCord joins the Army, where he learns to jump out of planes, becomes a sniper, and is assigned as a Special Forces (Green Beret) combat advisor in South Vietnam. Set in the early stages of the Vietnam War, no one can be trusted, and nothing is normal or expected.

Between Heartbeats tells the story of war's brutal and ugly elements, woven in with the creative and humorous ways those involved cope with them, as well as an even more unexpected and adventurous post-war life.