The cask of amontillado is about a man named montresor who wanted revenge on a man named fortunato cause of an insult that was made. They meet at a carnival and montresor lured him into his home to bury him alive.
The detail "...make sure they are not touching each other..." best supports the inference that one bad apple can spoil all the others. As stated in the text, the fruits are stored in the hoard house for future consumption. It is important that one does not contain a bruise since this will also affect the others around it.
