I love the Mad Hatter idea because the thing that bothered me about MM breaking out of jail with the key was – where was she going to go??? It’s not like she can leave town. Everyone knows who she is and everyone knows she’s the murder suspect. There are only so many places she can hide and I’m guessing that Regina would hire other people to look for her because she would say that Emma didn’t do her job if MM broke out of jail. But if the Mad Hatter left the key and kidnapped Emma then things look very different.