When Gus Dempsey joins the US Marine Corps, he knows without a doubt that he will make a great dog handler. He's always been good with dogs. In fact, he's often better with dogs than he is with people.

But Loki is not the dog that Gus was expecting. Fun-loving and playful, Loki acts more like a pet than the well-trained, bomb-sniffing Marine that he's supposed to be.

When Gus and Loki deploy to Afghanistan, though, they have no choice but to learn to work together. Because in war, getting along is a matter of life and death.