The narrator faints at this point and decides that it was a dream when he wakes again. But slowly, he realizes that it was no dream. He remembers that Selim Bahadur's case was still with the Count's bones which hadn't been disturbed.
The narrator falls asleep at this point and considers it a dream when he wakes up again. However, gradually, he understands that it was not a dream. He recalls Selim Bahadur's case remained with the Count's bones, which were untouched.