Why does Montresor keep suggesting that they go back?
As Montresor led Fortunato deeper and deeper into the underground vaults, he repeatedly suggested to Fortunato that they turn back; more than once, Montresor expressed concern regarding the possible dangerous effects of the niter hanging from the walls upon his Fortunato's health. Of course, Montresor was not truly concerned for Fortunato's well-being, but seemed to want to prevent any suspicions of his having any other motives than those related to the eo from entering his "friend's" drunken mind. In addition, Montresor relished his role as an avenger of the supposed wrongs against him; he enjoyed Fortunato's suffering and derived pleasure from the trickery he used against the man, as well its results. Suggesting that he and Fortunato turn back and not venture further into the vaults amused Montresor, since he knew that doing so would drive Fortunato to continue onward.