A tale of a brave-but-undersized pigeon named Valiant (Ewan McGregor), who dreams of joining the elite Royal Homing Pigeons Service (RHPS), and serving crown and country during World War II. Despite his small stature, Valiant's ambitions are enormous as he keeps a stiff upper beak and endures rigorous training in preparation for a dangerous mission to deliver vital messages to troops behind enemy lines. With a shortage of wingpower in the royal fleet due to increased attacks by a brigade of vicious enemy falcons (led by the ruthless General Van Talon), the mission falls to Valiant and the unlikely heroes of Squad F to try and save the day.