There is no cask of Amontillado. Montresor is only using an imaginary cask of imported wine to lure Fortunato into his underground vaults and catacombs. Montresor says several times, "I have my doubts." It is only because he pretends to have doubts about the authenticity of the nonexistent Amontillado that he can ask Fortunato to come with him to sample it. If for any reason Fortunato declined to come to Montresor's palazzo that night, he would undoubtedly question Montresor about it the next day; and Montresor would have to produce a sample of the so-called Amontillado. This is another reason Montresor expresses serious doubts about whether he has bought the true Amontillado or an inferior Spanish sherry. If Montresor failed in springing his trap on the night he encountered Fortunato, he would probably bring him an unlabeled bottle of sherry as a sample. Fortunato would taste it, pronounce it bogus, and that would be the end of that attempt on his life. But Montresor is an extremely patient man, and he would be thinking of some other means to murder his enemy without getting caught. Montresor twice inquires whether Fortunato is expected anywhere that night and feels assured that he is not. First Montresor says, in part, "As you are engaged." Then, since Fortunato does not give him the information he seeks, he says, in part, "I perceive you have an engagement." And this time Fortunato says, "I have no engagement; come." Montresor would prefer that Fortunato should be missing at least overnight, so as to leave a cold trail when an investigation was finally started.