When Mario and Luigi win a mansion in a contest they never even entered, Luigi's smells foul play, but with Bowser and Bowser Junior defeated, who could this potential trap be from? When Mario, Toad and Toadette go missing shortly after moving into the house, Luigi sets off with best "friend" Princess Daisy in tow, where they are given ghost-busting equipment from a strange scientist. With the Poltregust at their disposal, Luigi and Daisy must navigate their way through a series of spooky chambers to save their friends.