According to the typescript of Dracula that surfaced in the early 1980s and is now owned by a private collector, the original ending was different from the one we now have. What follows below is a section that was deleted. It originally followed the line "The Castle of Dracula now stood out against the red sky":
As we looked there came a terrible convulsion of the earth so that we seemed to rock to and fro and fell to our knees. At the same moment with a roar which seemed to shake the very heavens the whole castle and the rock and even the hill on which it stood seemed to rise into the air and scatter in fragments while a mighty cloud of black and yellow smoke volume on volume in rolling grandeur was shot upwards with inconceivable rapidity.
Then there was a stillness in nature as the echoes of that thunderous report seemed to come as with the hollow boom of a thunder-clap - the long reverberating roll which seems as though the floors of heaven shook. Then down in a mighty ruin falling whence they rose came the fragments that had been tossed skywards in the cataclysm.
From where we stood it seemed as though the one fierce volcano burst had satisfied the need of nature and that the castle and the structure of the hill had sunk again into the void. We were so appalled with the suddenness and the grandeur that we forgot to think of ourselves.
Given that the typescript shows considerable emendations in Stoker's hand, we can assume that he made the change himself. As for why, we may never know. Some suggest that Stoker had a sequel in mind; others that his original ending was too imitative of Poe's "The Fall of the House of Usher."
Thanks to Elizabeth Miller
added to Dracuals.info: 10 May 2007