London, 1859. After years fighting for Queen and country, Jack Lark walks back into his mother's East End gin palace a changed man. Haunted by the horrors of battle, he longs for a life of his own. But the city has altered almost beyond recognition, and Jack cannot see a place for himself there. A desperate moment leaves him indebted to the Devil—intelligence officer Major John Ballard, who once again leads Jack to the battlefield with a task he can't refuse. Europe is about to go to war. Jack Lark will march with them.