armadagon asked: Mark, if my opponent has Dr. Julius Jumblemorph and I have Mary O'Kill with a Curious Killbot in hand, can I use Mary O'Kill's ability to swap Dr. Jumblemorph with the Killbot in my hand? If so, whose hand does Dr. Jumblemorph go to?

You can. Your opponent’s Julius Jumblemorph would change to your control and end up in your hand. The Killbot would go to your opponent’s control on the battlefield. Note that your Mary has to be on the battlefield to do this. Remember to exchange them back at the end of the game.