The answer is: He tricks Fortunato into visiting his cellar.
In "The Cask of Amontillado," by Edgar Allan Poe, Montresor makes Fortunato go down into his cellar pretending he wishes to make him taste his wine during the carnival. Of course, Fortunato gets drunk in the catacombs, so Montresor can take revenge, chain him to the wall and bury him alive by leaving him in an enclosed place.
