When soldiers visit his Yorkshire home in 1917, an aloof farm dog finds himself unwillingly drafted. Taken from his quiet home and family, Griffin is cast into a world of noise and army drill at the British War Dog School. Here, scores of canines are being prepared for their roles as messengers, guards, or sentries. Bewildered and miserable, Griffin can think only of getting back to his farm. His new handler, Private Rosen, must win him over if the two are to have any hope of making it through the grueling training for messenger teams.
Little does Griffin know his trials have scarcely begun as fate pushes him closer and closer to one of the most horrifying events in history: World War One—the Great War.