Chapter 17 is the first time in the novel when all of the protagonists are finally together. These six
people--Mina, Jonathan, Dr. Van Helsing, Dr. Seward, Lord Godalming (Arthur), and Quincey Morris--will confront the evil represented by Count Dracula. They must undertake the task by themselves since no authority or outsider would possibly believe their story. These six people, of course, have positive proof of the existence of vampires. In fact, Jonathan feels rejuvenated in health now that he is confronting the evil Count head-on. Stoker is dependent on the tradition that only a few people are privy to information which exposes them to the dangerous forces of the supernatural, thus isolating them from the general populace. This is a standard device of many a thriller and gothic romance.
Chapter 18 is a key chapter of the novel, because for the first time Stoker defines the vampire and its supernatural powers, strengths, and the means by which the vampire can be entrapped. In all subsequent stories concerning vampires or Dracula himself, Stoker's parameters have been used--the garlic, the crucifix, the wooden stake, the holy wafers, etc. This chapter, then, defines the very essence of what constitutes vampire literature. Other authors may vary or slightly redefine these parameters, but the more traditional material concerning vampires is presented here.
The later portions of Chapter 19 present us with the first clue, however slight, that Mina Harker is to become the vampire's next victim. It is not by accident that he chooses Mina as his next victim; she is the wife of Jonathan Harker, whom the vampire encountered in Transylvania, and she was the closest friend of his last victim, Lucy Westenra. It is interesting that we are made aware of the Count's visit by the impressionistic writing of Mina herself. For example, she records things in her journal which she does not fully understand or associate with vampirism, but the reader, through dramatic irony, is fully aware of what is transpiring. There is a curious ambiguity presented in this chapter, as to how the vampire gains entrance to Mina's room. Recall that Van Helsing stated that vampires cannot enter a place without first being invited. The reader, at this point, does not have any idea as to how the vampire entered the room, unless it was because of the actions of Mina herself.
