Sigmund Rosenblum is on a mission in Russia. His train is stopped and he is arrested, but he escapes and travels to London. There, he compromises Margaret Thomas, the young wife of a rich clergyman.

Intelligence from Reilly in Port Arthur enables the Japanese Navy to sink the Russian Pacific Squadron. Margaret Reilly has an affair with Greenberg and leaves her husband. Reilly is seized by the Russians.

Reilly is posted to a German munitions factory, with the mission of stealing the designs of a new naval gun.

Reilly is in France, searching for Margaret, his wandering wife, and an Australian oil tycoon, and also competing with the Rothschilds to buy oil concessions in the Middle East.

On a mission to St Petersburg, Reilly investigates a deal for German shipyards to rebuild the Russian navy.

Reilly has fallen in love with Nadia, the wife of his friend Count Massino, and his lawyer friend Grammaticoff has some advice for him.