Mittens has x-ray vision
but instead of seeing through everything, she can only see through wood.
So if there's something on the other side of, say a wooden door... See the criminal?
She sees the criminal and saves the day,
much to the dismay of the police and the mayor cause you know they hate it when people take the law into their hands.
She's like a vigilante! ...uh cat. A cat who is a vigilante.
