By drinking a vial of Vampire blood, Rentt Faina, Undead adventurer, successfully achieved his next stage of Existential Evolution and has become a Lesser Vampire!Rentt, now short on funds, sets off on a journey to retrieve items required to craft equipment and weapons for his discple, Alize. With his faithful mouse familiar, Edel, Rentt sets off to the Labyrinth of the New Moon, slaying his share of Forest Wolves and Lizardmen. But is he prepared for the legendary monster that's appeared in the labyrinth's boss chamber, in place of the usual Earth Dragon...?Meanwhile, a Priestess-Saint and Gold-class Vampire hunter shows up at the doors of the Stheno Trading Company, where the sale of the Tarasque is to be negotiated. But they're here for one reason: the suspicion that a certain adventurer is actually a vampire in hiding...An Undead with a dream, eternally striving toward the rank of Platinum-class, even in undeath! All this and much more in the fourth volume of Rentt's undead adventures!