In JUSTICE SOCIETY: WORLD WAR II, Barry Allen (Matt Bomer) is on a picnic in Metropolis with his longtime girlfriend, Iris. However, when he sees Superman (Darren Criss) in a heated battle against Brainiac, Allen transforms into The Flash to join the fight. When Brainiac fires a kryptonite bullet at Superman, The Flash races to stop the bullet, but while doing so, he runs so fast, he goes back in time, and finds himself in the middle of a battle during what appears to be World War II. He soon meets Wonder Woman (Stana Katic), Black Canary, and the others who make up the Justice Society: a top-secret group of superheroes who have been sent by the United States to help in their battles against Nazi Germany. They are also helped by a reporter named Clark (who goes by "Shakespeare"), who provides eyewitness accounts of the battles while leaving out the role the Justice Society plays in the battles. Wonder Woman and the rest are initially distrustful of The Flash (who they call "Future Boy," since there already is a Flash on their team), but The Flash/Future Boy proves that he's on their side after he helps in a battle against the Nazis and saves Col. Steve Trevor's life. The Flash soon realizes that he hasn't gone back in time, but has ventured into a parallel universe. He joins the others to try to rescue Dr. Fate, who has been taken prisoner in a heavily guarded Nazi fortress, and is the only one who can crack a coded message that Trevor has found. After infiltrating the fortress, Dr. Fate decodes the message and sends them to the Bermuda Triangle. Getting there by submarine, they soon get into a battle with Nazi warships, but they're saved by Atlantean soldiers, who take them to Atlantis to meet Aquaman. However, Aquaman has been brainwashed by The Advisor, and takes the Justice Society prisoner. They soon learn that Aquaman, due to The Advisor, is a Nazi collaborator. The two Flashes help the others break out of the prison, and now the Justice League must stop a full-on invasion by both the Nazis and Aquaman's army as they try to invade the eastern seaboard of the United States.