In the winter trenches and flak-filled skies of World War I, soldiers and pilots alike might avoid death, only to find themselves imprisoned in Germany's archipelago of POW camps, often in abominable conditions. The most infamous was Holzminden, a land-locked Alcatraz of sorts that housed the most troublesome, escape-prone prisoners. Its commandant was a boorish, hate-filled tyrant named Karl Niemeyer who swore that none should ever leave.

Desperate to break out of "Hellminden" and return to the fight, a group of Allied prisoners led by ace pilot (and former Army sapper) David Gray hatch an elaborate escape plan. Their plot demands a risky feat of engineering as well as a bevy of disguises, forged documents, fake walls, and steely resolve. Once beyond the watch towers and round-the-clock patrols, Gray and almost a dozen of his half-starved fellow prisoners must then make a heroic 150 mile dash through enemy-occupied territory towards free Holland.

Drawing on never-before-seen memoirs and letters, Neal Bascomb brings this narrative to cinematic life, amid the twilight of the British Empire and the darkest, most savage hours of the fight against Germany. At turns tragic, funny, inspirational, and nail-biting suspenseful, this is the little-known story of the biggest POW breakout of the Great War.