November 1917. The first great allied tank battle takes place at Cambrai in the Pas de Calais. At first it proves a rousing success but after a hard fought two weeks German forces repulse the British on every front.

Reserves called up in support of the retreat include five hundred American engineers, including captain Colin Cahoon, a deeply religious Texan. Cahoon is injured during an enemy shell bombardment and wakes up in a hospital bed to find he is being treated by the enigmatic Dr Spindrift.

Cahoon finds himself embroiled in a titanic struggle that will stretch the Texan's religious beliefs, his sanity and his courage to breaking point. During the final year of The War To End All Wars, the future of all mankind will be decided.