The Great War is finished, and the world is at peace again. Conflict has been banished; international treaties guarantee it. Optimism pervades the day, and jazz rules the night; changed morals and fashions have created a new age. But Linus Smith knows that behind the agreements and the conferences, unseen by the carefree public, new forces are rising to take the place of those destroyed in the war. Secret battles are fought in elegant drawing rooms and in deserted alleys. And after four years in uniform, Smith finds that his cloak and dagger still fit him well enough.