Johnny takes an interest in a disheveled man that enters a diner, and buys him dinner. In gratitude, the man says he was born in 2414, a time of perpetual peace and quiet, which bored Landor, so he uses an old time machine to travel back to 1946, but is trapped when the machine disintegrates. Johnny is skeptical, but when a prediction of Landor's occurs, the JSA accepts Landor's challenge to them: the present knowledge of science versus the future knowledge of science. Wonder Woman writes down the six locations where Landor will strike, and the members get their assignments and head out.; Entering a den of thieves, Landor asks to see the boss and has to prove himself before the crooks agree to team up with him for the promise of big monetary rewards. Their target is the U.S. Mint, where Hawkman is waiting. A clash involving future science weapons stymies the Hawk, who is pinned down by a weird fountain pen's ink! Trying to fight back, Landor grabs Hawkman's gravity belt of Nth metal and soars into the sky with his men hanging on for dear life. Hawkman then heads back to his lab for an extra gravity belt.; Landor, having lost a few of his men, shows the rest of his mob a simple vacuum cleaner, which he takes and makes into a weapon he plans to use on local merchants. The Atom comes to town in time but almost becomes a victim of the weapon. The local bankers are being blackmailed for $1 million, so Atom enters the sewer system, emerging to take on Landor's henchman. The bankers emerge from a meeting, yelling to hang Landor, so the villain asks his men his automatic pencil. As Landor darts into the sewer system, he uses the pencil as a flame thrower to drive the Atom and the bankers back.; Towing a pile of junk, Landor and his remaining gang members flee into the desert, where Landor uses a home-made "mono-magnet" to lift the metal scrap from the back of the truck and onto the ground, where he contructs a machine that gives off vibrations that paralyzes all electronically-driven motors over the radius of 1000 miles. He plans to use it to disable nearly 1/3 of the nation unless his demands are met. The Flash dismantles the machine, captures some of the gang, and outwits Landor, who steals away under the cover of invisibility.; Landor heads to the city zoo with four men, and takes a new form of glutamic acid and feeds it to the elephants and a gorilla, giving them a form of simulated intelligence. Dr. Mid-Nite is confronted with the beasts charging out of the zoo and through the doors of the electric works, where Mid-Nite comes face to face with Landor, who tells him that the animals will destroy the plant unless his demands are met. Dr. Mid-Nite throws a blackout bomb, chloroforms the animals, then produces an electric storm in the room Landor and his men are hiding.....but Landor escapes.; Landor, with two members of his gang left, takes a gun from one, disassembles it and re-assembles it into a weapon that can change the molecular structure of any object. G.L. arrives as Landor and his men enter a jewery store, and his boys start taking the jewery when G.L. enters and it's Landor's weapon versus the power ring. At first it's a stalemate, but G.L.'s will power is too much and Landor runs, but not before he turns the ray on the jewels, making them valueless. Green Lantern recovers and is told by the store owner that the jewels in the display case were paste, so no harm was done.; Landor vows to get even with the JSA. Landor challenges Johnny to a duel with each performing magic tricks and the best magician wins. Johnny doesn't know that Landor wants him to win and capture him. Only then can Landor use his special gun on the JSA members all at once! The two match trick for trick, then Landor takes a Chinese finger puzzle and asks Johnny what it's for. Johnny, as usual, gets his fingers stuck in both ends (the T-Bolt frees him), then Landor sticks his fingers in it and captures himself. Johnny is so amazed, he faints, and Landor picks him up and takes him to JSA HQ.; As Landor is brought into JSA HQ by the T-Bolt, he pulls out his converted flashlight weapon to destroy all the members, but the Flash speeds over and knocks it out of his hand, and Green Lantern destroys it with his power ring. Now the puzzled JSA tries to figure out what to do with Landor. They can't put him in jail, because he'd find a way to make a weapon to get himself out. Green Lantern comes up with the solution: use his power ring to send Landor back to the year 2446. Now back in his own time element, Landor now decides that the modern era is not so bad after all!