Eleven-year-old Gregor and his two-year-old sister, Boots, are down-to-earth kids, literally and figuratively. Twice now they've tumbled down tunnels beneath New York City, first from their apartment building basement, then from Central Park, into the Underland to pursue adventures, decipher prophecies and defeat evil doers in the guise of giant rats and ancient aquatic reptiles. And in their wake they've left reviewers gasping with praise and readers clamouring for more.
In Suzanne Collins's second novel in the Underland Chronicles, it's early December and Gregor is in hot pursuit of baby sister Boots who has been spirited away down the Central Park tunnel by humungus but friendly Cockroaches to return her to Regalia and protect her from the evil gnawers led by Gorger. The rats want to kill her to stop Gregor from annihilating them and the rat known as Bane. The forecasts of death and who is to do what to whom and when are spelled out in the Prophecy of Bane, which like the earlier Prophecy of Gray in Book One of the Chronicles is best understood in retrospect when "it seems clear as water."
With the frightfully prophetic line, "Die the baby" etched in his brain, and with baby sister, Boots, on her way back to Regalia, Gregor sets out to find her, release his "Rager" emotions as a warrior, and track down and kill the Bane. With rapid-fire, page-turning action he catches up with Boots before he and his intrepid friends, new and old (Ares his bat bond; Mareth an Underlander warrior commander; Twitchtip, a friendly rat with a super sensitive nose for trouble; Luxa, Regalia's 16-year-old Queen in waiting; Harold, her 16-year-old cousin, their bat bonds and two huge comically quarrelsome firefly Shiners, Photos Glow-Glow and Zap) sail across the Waterway. During their travels they encounter a truly nasty squid, survive a whirlpool, subsist on raw fish, and run afoul of a black cloud of bat-eating mites from which Ares barely escapes but another bat doesn't.
Then in the confusion of a battle Luxa and Boots go missing and Mareth is seriously wounded. Gregor demands that Harold accompany Mareth back to Regalia and determines that in light of the Prophecy it is his responsibility to find and slaughter the Bane. He and Ares continue the deadly quest but when they encounter the white rat, they encounter something unexpected. They resolve a dilemma in a most surprising way and return to Regalia where Boots happily awaits them, having been flown in earlier on an oversized moth. Unfortunately, Luxa is still missing and a trial for conspiracy to commit treason awaits Gregor, Harold and Mareth. The trial's outcome hinges on the interpretation of the Bane prophecy by Regalia's interim Queen, Nerissa, a seer of sorts. She interprets in Gregor's favour but he is nevertheless advised to leave Regalia immediately.
Glad to be back home and reunited with his family for Christmas, Gregor knows he'll be returning to Regalia in the near future to The Prophecy of the Blood. And what we know from his previous adventures is that there'll be a cadre of finely drawn characters, good and bad, to meet him, lots of excitement to get his Rager blood flowing, and an evildoer or two from Gorger's rat pack to be slain. And he'll do it all with typical teenage panache and the right mix of humour and humility.