The Clockwork Prince picks up where the Clockwork Angel lets off, the second installment in The Infernal Devices prequel trilogy. Although the Shadowhunters continue to unravel the mystery of the Magister and the Pandemonium Club, they face a challenge of their own. Charlotte and Henry in charge of the London Institute are being undermined by a rival Shadowhunter—cough cough Benedict cough—who wants to control the Institute himself. The Consul gives Charlotte and the Shadowhunters of the Institute only a few weeks to find Mortmain, an impossibly difficult task, or face having the Institute ripped from them and given to others.
Meanwhile, Tessa and Will had "words" between them at the end of the last book and now there's a lot of awkwardness and suppressed emotion. We learn something about Will—that mystery in him which only tantalizes us in Clockwork Angel—that goes a long way in explaining his attitude and issues. He enlists Magnus Bane's help to solve this...er...problem. All I can say without spoiling anything that it is the reason Will holds back.
Meanwhile—again—the Shadowhunters find out about Mortmain, that he is a disgruntled warlock and son of warlocks who wants revenge on the Clave for a perceived wrong. But delving into his past also causes Tessa, Jem, and Will a glimpse into Will's past. And along the way we come a little closer to understanding who and what Tessa is. We also get a closer, sobering look at the Pandemonium Club, meet up with Tessa's brother, and meet the Lightwood boys.
Finally, the book ends with revelations (think Benedict Lightwood), more betrayal, a giant clockwork monster, broken hearts, and a glimmer of redemption that makes it all worth it. I can't wait to read the concluding book: Clockwork Princess. Throughout it all, Cassandra Clare flawlessly weaves elements of urban fantasy, historical fiction, and steampunk together into one fantastic whole.
A great quote from the book, which is exactly how I feel about books and libraries: "There was something about the smell of books, the ink-and-paper-and-leather scent, the way dust in a library seemed to behave differently from the dust in any other room—it was golden in the light of the witchlight tapers, settling like pollen across the polished surfaces of the long tables."