The trickster Mr. Mxyzptlk is partnering with Lex Luthor in a new scheme to take down Superman. After responding to a fake alarm, the Man of Steel is caught in a red kryptonite cage and must meet Luthor's demand to crush a mountain of coal into diamonds. But with the kryptonite zapping Superman's strength, the task is impossible. That's when a disguised Mxy appears with a deal. He'll help... if the super-hero gives up a super ability. Will Superman discover who he's truly dealing with before losing all his powers for good?