The cryptid catcher

Clivo Wren is thirteen when he discovers that his father, who died not long ago, never worked as the archaeologist the family believed. He was secretly a cryptid catcher, a hunter famous for tracking down rare mythological beasts. Clivo now has to take up his father's work and go after a creature whose blood can make its drinker immortal. He has to reach it before anyone who would misuse that knowledge does.