American brothers, Max and Chris, arrive in a small European town to spend the summer with their eccentric uncle Gustav. Max becomes sure that their uncle is a vampire and goes to see the rich local businessman Alexander Lucard for help.
Gustav's old friends Peter and Anna Dyson arrive for a visit. Meanwhile, Lucard finds out that Max has taken the Cross of the Magyars which prevents vampires from entering Gustav's home from the house to be blessed.
While Sophie and Chris skirt around the relationship issue between them and finally end up on a date together, Max meets a clumsy, but brilliant, scientist who has made it his life's work to invent items for battling the undead.
When a man named Paul Yeager loses his wife to Lucard's second-in-command, Klaus, he attempts to enlist Gustav to help him kill the vampire, but Gustav is strangely unwilling to help. Meanwhile, the children go on a treasure hunt.
Gustav appears on "Cleo Talk" to debunk a professional psychic, Lana Zorro, but she astounds him when she is able to read his mind. Meanwhile, the kids find Dracula's tomb.
The rich and famous Contessa de Suarez has chosen Sophie to be her guide while she's in town. When Sophie learns that the Contessa is staying with Lucard, she grabs Uncle Gustav's vampire hunting equipment and rushes to the castle.
Helsing invites lounge performer Mycroft Tickler home for dinner, only to discover that he is brother to Magnus St John Smythe, the bungling inventor of the anti-vampire laser gun, and that Lucard has invited him to dine at the castle.
Lucard gets sick after drinking blood from a young thief and sends for Dr Gabor Varney. The cure is a compound found only in the waters of Paquette spring. Helsing and Max follow the dying Lucard to the springs to destroy him.
Inspired by Pygmalion, which the musical My Fair Lady was based on, Lucard decides to turn a ditsy woman who works for him into a true lady. Meanwhile, Gustav's old senile friend claims that vampires are preying on his old folks' home.
Max gets the offer to publish his first novel only to realize that it got switched with the one from Gustav's friend about true identities of vampires hiding among humans. Meanwhile, Lucard invites the author and his wife to dinner.
Gustav investigates why the schnitzel he ordered from a restaurant never arrived. Meanwhile, Lucard discovers that someone is creating subpar ghouls. Also, Max and Sophie start an experimental band which, surprisingly, gets big in Europe.
A clip show in which Lucard invites everyone to dinner and they remember the misadventures they had together throughout the season. However, Gustav remains suspicious.
When the boys' mother arrives at the end of summer to pick them up and take them home, they learn that she has a new business partner - Klaus. Gustav discovers a time hole in Lucard's castle that keeps Lucard young.