Luigi embarks on a dream vacation with Mario and friends upon receiving an invitation to a luxurious hotel. However, his dream quickly becomes a nightmare when King Boo reveals everything had been a ploy to capture Mario and friends. With the assistance of Professor E. Gadd once again, the reluctant and cowardly hero Luigi traverses up and down treacherous floors of the now-ominous hotel on a quest to save them.

Luigi embarks on a dream vacation with Mario and friends upon receiving an invitation to a luxurious hotel. However, his dream quickly becomes a nightmare when King Boo reveals everything had been a ploy to capture Mario and friends. With the assistance of Professor E. Gadd once again, the reluctant and cowardly hero Luigi traverses up and down treacherous floors of the now-ominous hotel on a quest to save them.