A vial of poisonous hydra blood with the potential to kill millions has been unearthed! Jorge, Fiona, and Marcus must embark on an urgent mission to keep the modern world safe from the hydra's poisonous blood. The monster hunters travel back in time to stop the Greek demigod Heracles from killing the hydra, learning about ancient Greek civilization along the way. Travel with them through the streets of the city-state of Argos and the spooky shoreline of Lake Lerna, where they encounter the mysterious nine-headed hydra. This graphic novel includes monster profiles and survival tips as well as in-depth content on the social structure, government, and fashion of ancient Greece. Backmatter includes an activity page and character information.