April 1919. Scarred and disillusioned, John Griffin has returned home from the Great War with no job and no real prospects. He is contacted by Harry Armistan, a very worried father and a rich New York City financier. While on her honeymoon, Harry's daughter disappeared from her London hotel. Armistan enlists Griffin to find her after receiving a recommendation from Griffin's former marine commander. With nothing better to do and against his better judgment, Griffin agrees. He returns to England and his haunted past. There, his only lead is the missing girl's widowed sister-in-law. Intrigued by the young widow, violence and mystery follow.

The clues lead him to Paris, a city just beginning to recover from four long years of war. He encounters a host of diverse characters reveling in the war's end, while still mourning their losses. With the help of this unlikely group, Griffin narrows his search. But as he closes on his quarry, he stumbles upon a terrible plot, which threatens to shatter the world's chance for peace.