Cirque Du Freak: The Manga, Vol. 3: Tunnels of Blood — Darren Shan

Accompanying his master, Mr. Crepsley, on a trip to the city,
half-vampire Darren Shan is ready to enjoy a pleasant holiday away from
the Cirque du Freak with his friend Evra. But when he learns of a string
of grisly murders whose victims have been drained of blood, Darren
begins to suspect that his mentor may be involved. Has Mr. Crepsley
crossed the line, or could it be that some creature more fearsome than a
vampire haunts the city's streets?