The Heroes in Training are entering the Underworld--if Hades can conquer his canine fears, that is. The Underworld usually isn't really meant to be a fun place--but tell that to Hades He loves the dark and the stinky smell of sulfur. However, there is one thing that Hades is not a fan of: dogs. And when Zeus and his fellow Olympians encounter Cerberus--a snarling, three-headed dog--Hades must conquer his fears and tame the hound so everyone can continue...