Superman #271

As WGBS employess picket outside the building, they witness a mirror image of the Metorpolis skyline descending from the sky. When Superman investigates, he finds Brainiac, who announces that when the mirror image meets the real skyline, the latter will explode. With the aid of WGBS, Superman convinces Brainiac that his plot has succeeded and that he is mad with rage. With the advantage of his sanity and Brainiac's misunderstanding of the situation, Superman is able to turn the tables on Brainiac and send him off into deep space.