|Appeared in||Superman Returns|
During the years that Superman disappeared into space, Lex Luthor got out of jail with the help of an unsuspecting elderly beneficiary, whom he conned into marrying so he could get at her wealth after she died. With the money, Lex hired out a new set of goons and then traveled again to Superman's Fortress of Solitude, where this time he talked with the hologram of Superman's father Jor-El, wanting to know everything about Kryptonian crystals.
Returning to the widow's mansion, Lex Luthor has one of his men chip away a portion of a Kryptonian crystal from the Fortress of Solitude, planting it in the water of her immense train set layout. After a minute or so of waiting to see its effect, all the lights suddenly go out. They soon go back on, and as Lex and his gang continue to watch, a crystalline structure emerges from the water, ripping through the floor of the mansion.
As Lex Luthor looks out over the harbor from the balcony of the widow's mansion, he sees the Daily Planet newspaper headlining THE MAN OF STEEL IS BACK. This means he's got the challenge of the century on his hands again to deal with. He greets part of his gang out in front as they unload a metal containment box from a van, indicating that it was stolen property. Luthor tells them to modify it and attach it to the ship.
While Superman deals with a woman in a runaway car tearing through the streets at night, Luthor and his gang go into the Metropolis Museum near closing hours, looking for a valuable rock. Some of his goons find the main power switches and shut down all power in the museum, allowing Luthor to use his special stethoscope to find that particular rock with a certain radiation frequency. He soon spots it as the rock emits green sparkles. The power soon goes back on, and the rock now turns up missing. The woman whom Superman rescues turns out to be Luthor's henchlady Kitty, who slaps her boss for cutting the brakes on the car without her knowing about it, though her distraction has still achieved its end.
With the stolen rock being Kryptonite, the only substance that can weaken and kill Superman, now in Luthor's possession again, he has the sample shaped into a cylindrical casing for one of the memory crystals taken from the Fortress of Solitude and placed inside a torpedo with its explosive components removed. After kidnapping Lois Lane along with her son Jason, whom he had found snooping around the mansion, he took them on his ship to the coordinates where he would launch the missile, revealing to Lane and his associate Kitty that the grown land mass would end up displacing parts of other continental land masses, effectively killing billions of people in the process. He leaves Lois and Jason in the care of his thug Brutus while he oversees the launching of the torpedo containing the Kryptonite-encased crystal. After the launch, however, he discovers that Brutus was mysteriously killed by a grand piano hurled at him with great strength, and has Lois and Jason locked up in the pantry while he, Kitty, and his men take off on helicopter toward their newly-emerging land mass.
After Superman deals with the earth tremors in Metropolis caused by the emerging land mass and rescues Lois, Jason, and Richard White from the pantry of the now sinking ship, Superman arrives in the heart of Luthor's new land mass and confronts Luthor, unaware that the land mass is laden with Kryptonite, and demands for Luthor to give him back what was taken from his Fortress. Luthor, seeing sweat dripping from Superman's temples, responds by hitting the Man of Steel, causing him to fall to the ground and seeing the Kryptonite through its cracks. Luthor takes pleasure in repaying Superman for five years of his life lost in prison by using the weakened superhero as his punching bag, and then letting his thugs have a go at hurting the Man of Steel, humiliating him until Luthor finally shoves a jagged piece of Kryptonite into his back and watches him plummet into the depths of the sea.
Sometime later, though, the ground begins to crumble underneath Lex's feet and that of his henchmen when Superman, rescued by Richard White and with part of the Kryptonite piece removed from his back, uses his heat vision to separate the grown land mass from the continental shelf and to fly it far into space. Luthor and his assistant Kitty manage to escape the island before Superman flies it away from Earth. However, in their escape, Kitty secretly dumps the remaining memory crystals in Luthor's possession out of the helicopter and makes it look like an accident.
Lex and Kitty land on a small desert island with no gas left in the helicopter and no source of food available to them, until Luthor eyes the surviving dog from the elderly widow's mansion.