In the tradition of his popular Dr. Mabuse films (Dr. Mabuse: The Gambler, The Testament of Dr. Mabuse), Fritz Lang's Spies revolves around the baroque schemes of a criminal mastermind -- in this case, Haghi (Rudolf Klein-Rogge), a master spy who operates from a secret office inside a bank. The plot is a virtual template for all espionage movies to come. It's full of double agents, secret documents, assassinations, and even a love story between two agents on opposite sides of the vast game Haghi is playing. In contrast to Lang's silent masterpieces Metropolis and Die Nibelungen: Siegfried, with their gargantuan sets and stately, myth-like plots and pacing, Spies is made with swifter strokes. It begins with a quick-moving montage of murders, heists, and other crimes that sets the mood for the fast-paces, densely plotted action to follow. This, and a brilliantly designed and edited later passage which finds the hero, Agent 326 (Willy Fritsch), trapped in a train car about to be obliterated by an oncoming locomotive, are two of the film's great action sequences. Its ending, in which master-of-disguise Haghi's surprising secret identity is revealed, provides one of the most shockingly surreal moments in Lang's ouevre.