Spoiler Alert! This is a summary of the entire show, including the end.

Transylvania, late 19th century. Professor Abronius and his assistant Alfred travel from Germany to Romania, trying to find proof for the existence of vampires. They are separated in a snowstorm in which the professor almost freezes to death (He, Ho, He). Alfred helps the professor to safety and brings him to a nearby town where the villagers take care of them (Knoblauch). The innkeeper, Chagal, shows them to their rooms (Bitte, meine Herren) and Alfred catches a glimpse of Chagal's daughter, Sarah, who is taking a bath in their bathroom. Chagal sends her away and locks her in her room (Eine schöne Tochter ist ein Segen). The professor goes to sleep while Sarah and Alfred daydream about each other before doing the same and Chagal seduces the maid, Magda (Nie Geseh'n). At night, Count von Krolock visits the village and stands outside the inn, watching Sarah and preparing to take her away from her family (Gott ist tot). The next morning, Chagal, Chagal's wife, Rebecca and Magda sit outside doing chores (Alles ist hell) when Koukol, the count's hunchback servant comes to collect candles from the village. Abronsius and Alfred join the others outside and Abronsius tries to figure out what kind of secrets the villagers are keeping from them (Wahrheit). Later, back inside the inn, Alfred is getting ready to take a bath. Sarah, hearing Alfred draw a bath, sneaks out of her room to find Alfred looking through the peephole into Sarah's room. She approaches him flirtatiously and ends up stealing his bath (Du bist wirklich sehr nett). As she's bathing, von Krolock appears in the bathroom and seductively invites her to the midnight ball at his castle (Einladung zum Ball). Alfred interrupts the count's invitation and Chagal brings his daughter to bed, having her promise she'll never bathe again. At night, Sarah sneaks out of the house, ready to run off to the castle. Before she can run away, Alfred leaves the inn and starts singing for her outside her window. Afraid that someone will hear Alfred sing, Sarah interrupts him and tells him she's invited somewhere else. She tells Alfred he may come but he first needs to get her sponge (Draußen ist Freiheit). While Alfred is inside, Sarah imagines what it is going to be like dancing with the count at the ball (Stärker als wir sind/Das Gebet). She runs away before Alfred can follow her. Upon realizing what happened, Chagal runs after his daughter and is brought back dead from the woods the next day (Trauer um Chagal). At night, Magda inspects the body of dead Chagal and wonders about death (Tot zu sein ist komisch) when Chagal wakes up, having been turned into a vampire, and bites Magda. Alfred and the professor, wanting to have a closer look at Chagal's body, run into the vampire and have him take them to Graf von Krolock's castle (Durch die Wildniss zum Schloß). Soon after they arrive, Graf von Krolock opens his doors for them and introduces himself, then invites them to stay. (Finale 1. Akt).

At night, in Graf von Krolock's castle. Sarah wanders around the halls aimlessly, dreaming of becoming a woman. The count watches her for a while, then serenades her. He struggles not to bite her, knowing she will taste better if he waits until the ball. (Totale Finsternis). Meanwhile, Alfred is having a nightmare about Sarah and him dying (Carpe Noctem). When he wakes up the next morning he realizes it was just a dream and gets ready to look for the count's crypt with the professor (Ein guter Tag). The professor starts searching while Alfred packs their things. When he finds Sarah's sponge in their bag he remembers who he is putting himself in such danger for (Für Sarah, new versions). He follows the professor to the crypt (In der Gruft) where they find the count's and his son's coffins. Unable to do it himself, the professor sends Alfred to kill the vampires, however, Alfred is unable to so they are forced to leave the crypt. Meanwhile, Magda and Chagal wake up and fool around in the crypt (Geil zu sein ist komisch). Continuing their search through the castle, Professor Abronsius and Alfred find the count's enormous library (Bücher, Bücher). While the professor excitedly looks through all the books, Alfred hears Sarah singing and finds her in a nearby bathroom. He begs her to flee with him but Sarah refuses and asks him to leave so she can get out of the bathtub. Returning to the library, Alfred finds the professor still fascinated by all the books (Bücher Reprise). The professor tells Alfred that he can find the answer to any question he might have in a book, so Alfred finds a book to give him advice on love. While he reads, he thinks he hears Sarah sing again but runs into the count's gay son Herbert instead, who has clearly fallen in love with Alfred (Wenn Liebe in dir ist). Alfred manages to escape with the professor's help and they both leave the castle. Alfred tells the professor that while he was dancing with Herbert, he could only see his own reflection in a nearby mirror and is now sure that they are in fact vampires. Count von Krolock listens to their conversation and informs them that Alfred's soul is already lost (Sie irren, Professor). The count disappears and Alfred and the professor see the other vampires ascend from their graves to go to the ball (Ewigkeit). After they all disappear, Graf von Krolock walks across the now empty graveyard, remembers some of his victims and shows his feelings in the show's biggest solo (Die unstillbare Gier). He then leaves the graveyard to welcome his fellow vampires to their annual ball and promises them quite a feast. Alfred and the professor, having snuck into the celebration, have to witness the count kill Sarah (Tanzsaal). The professor assures Alfred that all Sarah needs is a blood transfusion to save her and, although now discovered by the other vampires, they manage to run away with Sarah. Once away from the castle, Alfred holds the tired girl in his arms and they dream about their freedom. While they rest, Sarah turns into a vampire and bites Alfred before he realizes what is happening (Draußen ist Freiheit - Reprise). Both of them run away (Tanz der Vampire - Finale 2. Akt).