On the journey are Darren Shan, two of the Little People, and Mr. Crepsley; they also run into Mr. Crepsley's old friend, Gavner Purl in a way station. The way station is a place where vampires rest while ascending the treacherous path to Vampire Mountain , where Darren and Mr. Crepsley see two broken coffins and vampire blood. Here Gavner Purl jokingly tries to kidnap Darren in the waystation and surprise the party. Mr. Crepsley, alert and unknowing of the man's identity nearly kills Gavner.

When Darren "falls in love" with Madam Octa, an enormous taratula from a freak show, he decides to steal her and train her to perform amazing deeds. But the spider bites his best friend, Steve, and Darren is forced to sell his soul to an evil vampire for the antidote.

Darren Shan, the Vampire's Assistant, gets a taste of the city when he leaves the Cirque Du Freak with Evra and Mr. Crepsley. When corpses, drained of blood, are discovered, Darren and Evra are compelled to confront a foul creature of the night who may prove to be the end of them all...

Darren begins to enjoy his life among the Cirque performers as the youngest half-vampire in existence, but he defiantly refuses to drink human blood -- the whole idea sickens him -- and he tries desperately to cling on to the part of him which is human.