On a routine traffic stop, a wanted felon got the better of him, and took him hostage. There were several times where Mickey thought he would lose his life. All he could think of was his beloved wife and his beautiful daughter.
The stress of the event, however, changed him. And the stress began to alienate his wife. After months of depression, she left him and that was the final stressor that changed him. Mickey had been exposed to mutagenic particles when he was a child (exploring the sewers where large amounts of the particles had accumulated). It was sudden and painful. The next time he looked in the mirror, his eyes were alien to him. Vibrant green with vertical pupils--exactly like a cat! He also discovered through trial and error that he was much stronger, and very agile. The final discovery was exuberant. He could vanish and reappear at another location, just by thinking about it.
He snapped out of his depression. He didn't know where his wife had gone, but he would spend some time looking for her. She had all but vanished. Mickey didn't understand it. He had never been a threat to her; there was no reason for her to be in hiding. To this day, he has never located her, or his daughter, and he continues to look. She may no longer love him, but he would like to see his daughter.
Mickey has adopted the identity of Cheshire Cat, and continues to serve the people as a champion. He appears suddenly from nowhere to protect those most in need.