By Suzanne Collins
The Hunger Games author's first series: a boy and his baby sister fall through a grate under New York City into a dark world of giant talking rats and bats, and a war he's prophesied to fight.
Eleven-year-old Gregor is stuck home for the summer minding his toddler sister Boots when she crawls into a grate in the laundry room and he dives after her. They fall a long way down into the Underland, a world beneath the city where pale humans live alongside giant talking bats, cockroaches, rats, and spiders. The Underlanders are convinced Gregor is the warrior of an ancient prophecy, and he agrees to a dangerous quest for one reason of his own: it might lead him to his father, who disappeared into this place years ago and never came home.
This is where the trail leaves the Greek gods behind for a purer test of stamina and stakes, and it's a superb one. Suzanne Collins, before The Hunger Games, builds a whole underground world with its own peoples and politics, and drives it with a prophecy and a war, the kind of scope a child heading for Percy Jackson wants. The emotional engine is Gregor's search for his lost father, which gives real weight under the adventure. It's tenser and sadder than the mythology books below it, which is exactly why it sits here, readying a child for stories where the danger is genuine. Four more books follow.