Miraclo the Magician was a stage performer that appeared live in front of packed crowds at the New York City Theatre in 1923. Believing his "pulling-a-rabbit-from-a-hat" trick would make him famous, he was unaware that he had been hypnotised and that the ordinary looking hat was actually a deadly alien device (a warp gate) that would enable the Lepus Warriors (a vicious army of giant rabbits) to jump between dimensions in their quest to conquer new worlds.
The Eleventh Doctor and Clara were on hand to ensure that no one came to any harm and the invaders were sent home. Miraclo did manage to achieve some fame with the help of a disappearing blue box in his act. (COMIC: The Hat Trick)