Having abandoned his old way of life to unwillingly serve as Mr Crepsley's assistant, Darren must accustom himself to the habits of vampires. But the change is difficult and the loneliness is crushing.

In an attempt to give Darren a sense of stability, Mr Crepsley takes him to live at the Cirque Du Freak, where he is to share a tent with Evra Von -- the Snake Boy introduced in Book 1. Darren soon fits into his new position -- even if he doesn't exactly enjoy hunting food for the ominous Little People! -- and he and Evra befriend a curious young boy called Sam Grest, whose one great wish is to join the travelling freak show.

But all is not well with Darren. He refuses to drink human blood, even though he'll die without it. While Mr Crepsley argues with him, and tries forcing him to drink, Darren grows weaker and weaker. Will he resist the temptation of blood and sacrifice himself for the benefit of his humanity -- or will some awful turn of events lead to his becoming a true, blood-sucking creature of the night???