Brain creates a new invention to turn him and Pinky temporarily into humans so they can take over the world! But when the machine breaks under pressure and him and Pinky are stuck as humans, him and Pinky must find a special artifact to fix the machine and change them back to regular little lab mice! They venture off to NYC, to break into the MET museum to hopefully find this special artifact to fix the machine. On the way there they meet 2 old "friends"