Wishing Mario & Peach luck on vacation,Luigi receives an invitation from Daisy to the Mansion. He ended up in the Boo Woods & found a Mansion where he is confronted by Ghosts,but was saved by Professor E Gadd.
In his Lab,E Gadd tells Luigi that this Mansion is ruled by King Boo & Daisy is held captive. Luigi assures him that if he's Mario's,He would save Daisy & E Gadd tells him that he knows about those two & sends F.L.U.D.D. to his location. He gave him his Poltergust 3000 to vacuum the ghosts.
While capturing the ghosts,Luigi encounters King Boo,who reveals that he was the one sent a fake invitation. Luigi fights with King Boo & defeats him,sucking him into the Poltergust 3000.
He rescues Daisy & E Gadd congratulations him. Luigi received a phone call from Mario & tells him all about it.