Mario was having a mid-day nap. Then he heard the usual "HELP" screams. Thinking it was Bowser, he went to the castle and saw Waluigi, Luigi's stepbrother capturing toads, goombas, even Bowser himself. Luigi arrived when Waluigi captured Mario. Then he hit a? block and got a star. Waluigi escaped with everyone he captured before Luigi could touch him (when he has star power every enemy he touches dies). Then a door opened and behind was a familiar room with a strange painting of...
Find out in chapter 2 ;)