Thomas and Ellen Hutter appear for all the world to be a young couple so enthralled by their romance that they could not possibly have a care in the world. Then arrives a stranger with the even stranger name of Knock who presents himself as real estate agent. Thomas, Knock promises, stands to make the kind of money that a young couple could really use just starting out. All that is required to journey to the ancestral castle of Count Orlock and complete the contractual business necessary for the Count to purchase a home not far from where Thomas lives.
Although Ellen is rather dismayed and unnerved by this idea, Thomas is sold. Ellen will be left behind in the trusted hands of friends while he is gone for just the few months it will take to get to Orlock’s home and back again. As he nears the castle later, Thomas stops for a meal in tavern and casually mentions his destination. At the very mention of the Count’s name, however, he is warned to turn back and head home and never lay eyes on Orlock. Dismissing the warnings as supernatural gobbledygook, Thomas heads forward to his appointment meeting. Upon leaving the tavern, however, a wolf appears and spooks the horses driving the carriage Thomas was in. Thus forced to spend the night in the tavern, Thomas comes across a volume with the rather forbidding title The Book of Vampires. He immediately opens to a passage warning against the possibility of always recognizing dangerous beasts when they appear. Spooked, he nevertheless laughs away his anxiety, determined to find someone who will take him to Orlock. The one person willing to do so will only take him as far a bridge and not beyond.
Once he crosses the bridge, a carriage moving at an alarming speed arrives to meet him. He steps in upon learning the carriage belongs to Orlock. When he arrives at the castle, however, nobody is there to greet him. He walks in and the doors mysterious close behind him. Finally, he comes face to face with Count Orlock.
While dining that evening, Thomas accidentally wounds himself with a knife and Orloff rapidly moves to lick the substance away from his finger, muttering “Your precious blood” as he does so. Now Thomas is truly and genuinely spooked, but he spends the evening in discourse by the fire with the Count until he falls asleep. When he awakes to discover two small bite marks on his neck, he assumes he has been the victim of a mosquito. The very next day the real estate transaction closes. Purely by accident, Orlock gets a glimpse of Ellen in a picture Thomas carries and he observes that she has a beautiful neck.
Back home, Ellen begins to fall under the sway of the Count. She begins sleepwalking and at one point wakes up from a nightmare in which Thomas seemed to be caught in a losing battle with Orlock. The very next day, Thomas discovers the coffin Orlock sleeps in and cowers submissively before it. By nightfall, Orlock is setting off for his new home aboard a carriage equipped with an abundance of coffins. The coffins make their way to a ship and the ship makes its way to the village of Wiesborb where Orlock’s newly bought home awaits. The ship’s journey eventually results in everyone aboard falling victim to Orlock’s need for blood and meanwhile Thomas is trying to make back to Wiesborg by horse before Orlock can get there first. Ellen has by this point fallen completely under the spell of the vampire.
When the ship arrives on land, Orlock is forced to carry his remaining coffin to his new home. Thomas manages to make it back home as the same time and takes Ellen into his embrace. The touch of her beloved gives her a newfound sense of safety. The death and devastation revealed upon the ship which brought Orlock to town is taken by the villages to mean the arrival of a plague which is only confirmed when the death toll of the town begins building immediately and grows with each passing day.
Knock, who has since been imprisoned on charges related to a lack of sanity, escape when he kills his guard and is subsequently chased through the streets of Wiesborg by the increasingly anxious townspeople. When Ellen starts to complain about being sick, Thomas leaves to retrieve Dr. Sievers, but while he is gone, Count Orlock enters Ellen’s bedroom. Just as he is about to finally sink his fangs into her neck, however, the rooster crows and the sun rises. When the rays of the sun make contact with the vampire, he vaporizes into nothingness and finally, forever, dies.