Gus Dempsey is a newly trained dog handler in the United States Marine Corps, and when he is deployed to Afghanistan he is paired with Loki, a bomb-sniffing black Labrador with a mischievous streak.

Newly arrived on the Western front and assigned as a medic, Rivera finds himself in the middle of the Battle of the Bulge, cut off behind enemy lines--and his only companion is a Nazi trained Doberman pinscher.