When the United States enters World War 2, Alan Scott-aka Green Lantern-enlists. In the European Theater, he fights as Captain Scott of the Army Corps of Engineers, refusing to use the lantern's power, succeeding in life-and-death situations through his native wit and intelligence. And then, Malvolio arrives.
Initially enemies, Malvolio and Scott agree to a truce, as each tries to convince the other to come over to his way of seeing things. But Malvolio is insane. He's not a Green Lantern but a power-hungry madman with a GL ring. He turns the tables on Scott and sends him into the nameless dimension in which Malvolio was imprisoned for centuries.
Hal Jordan, Earth's second Green Lantern, must free Scott and point him toward his destiny. But by the time Scott has returned to Earth, Malvolio has tracked down an army of humans and made them into his agents. Scott must now discover the full extent of his powers and use them to defeat both Malvolio and his army of sleeper agents, before they can destroy Earth and every other planet that a Green Lantern calls home.