John "Jack" Seward, M.D. is the administrator of the Seward Sanitarium, an insane asylum not far from Count Dracula's first English home, Carfax in Purfleet, Essex. Throughout the novel, Seward conducts ambitious interviews with one of his patients, R. M. Renfield, in order to understand better the nature of life-consuming psychosis, or as he calls it, zoophagous. As a psychiatrist, Seward enjoys using the most up-to-date equipment, including using a recording phonograph to record his interviews with his patients and his own notes. Several chapters of the novel consist of transcriptions of Seward's phonograph recordings. One of the main contributions made by Dr. Seward is his recordings of the events depicted from his personal perspective as a doctor; allowing the reader to gain a scientific understanding of the behavior of vampirism through his behavioral analysis of Renfield.

He is best friends with Quincey Morris and Arthur Holmwood. All three propose to Lucy Westenra on the same day. Although Lucy turns down Seward's marriage proposal, his love for her remains, and he dedicates himself to her care when she is suddenly taken ill.

He calls in his mentor, Abraham Van Helsing, to help him with her illness, and he helps Seward to realize that Lucy has been bitten by a vampire and is doomed to become one herself. After she is officially destroyed and her soul can go to heaven, Seward is determined to destroy Dracula.

Lucy describes as "one of the most resolute men" she ever saw, "yet the most calm". She notes that he has a 'strong jaw, good forehead' . She knows that he is intelligent and caring. She also notices by his fidgeting that he is a bit nervous. Little does she understand what is happening in that great mind.

Van Helsing certainly believed the tales about the Vampire they pursued. And he had seen with his own eyes Lucy, luscious lucy who had teased him and then chosen another, that Lucy had risen from the grave. To be sure, she was dead again and less likely to rise with the obscene stake jutting from her breast. But she had risen. And he had no doubt she had been dead. Her body had been cold and rubbery. He knew that for a fact.

And yet she had risen. Moved. Spoken. Lusted for life. He could not deny the evidence that Dracula had done something to her that had brought her back from the dead. That he had to have. To have the power of granting a second life, even if limited, even if restricted to certain hours of the day. He had patients in London who would pay thousands of pounds for just one day more.

And the level of command that Dracula evidenced over Lucy and now Mina. He had to have that too! The ability to command those he saved to do anything. His blood boiled with desire at the thought.

The others sought only to destroy the ancient monster. But he plotted instead to capture and control him. Put him in a cage and force the knowledge out of him.

For that, he would need a cage that could hold him, and stalwart men to transport that cage to a place where he could study his specimen at will.

Perhaps in the Count's own land? A plan was emerging in his head already.