The Iron Queen recap

Exiled from Faery, Meghan Chase and Ash are living in the mortal world when the Iron fey find them. The false king who took Machina's crown is expanding the Iron Realm far faster than his predecessor, and the iron creeping through the wyldwood is killing Faery outright. Glitch's Iron rebels want the usurper gone; Oberon and Mab want the same, and offer to lift Meghan's exile if she goes into the Iron Realm and kills him, since she is the only being who can survive there. Ash trains her to fight and then swears himself to her as her knight, Puck rejoins them, and Rowan turns up still serving the enemy. In the Iron Realm they learn the realm's history and how its crown passes, and Meghan works out what winning will actually cost. In the final battle she destroys the false king and then takes the loose Iron crown herself, becoming the Iron Queen, which binds her to a realm no ordinary fey can enter. She orders the dying Ash out of it to save his life and gives up her human family for good. Ash leaves vowing to find a way to earn a mortal soul and come back.

Previously: Meghan Chase discovered she was the half-human daughter of Oberon, king of the Summer Court, when Iron fey stole her little brother. She recovered him, destroyed their king Machina, and was warned as he died that the Iron crown would not stay empty. Paying the bargain that made the rescue possible, she went to the Winter Court as the hostage of Queen Mab, mother of Ash, the prince she had fallen in love with. Iron fey then ambushed the ceremony that passes the Scepter of the Seasons between the courts, killed one of Mab's sons and stole the Scepter; Winter blamed Summer and went to war. Meghan escaped to the mortal world, found Puck again, reached Leanansidhe the Exile Queen, in whose house she found her long-missing human father alive with his memory stripped, and with Puck, Ash, Grimalkin and the reformed Iron fey Ironhorse she stole the Scepter back. Ash's brother Rowan was exposed as the traitor working for the Iron fey, and Ironhorse died destroying the Iron fey Virus. Meghan stopped the war by returning the Scepter on the battlefield, but did it by openly wielding iron glamour, the power lethal to every other fey. Oberon banished her from the Nevernever, and Ash, who chose her over Winter, was exiled too. This book opens with the two of them in the mortal world with nowhere in Faery to go.

Exiled from the Nevernever, Meghan and Ash work their way through the mortal world toward Meghan's home in Louisiana, hunted along the road by things that should not be able to find an exile at all, including church grims and Iron fey scouts. Meghan wants to see her family before she works out what her life is now; what she learns instead is that banishment has not made her any less of a target. The Iron fey reach her first. Glitch, once an officer of the old Iron King and now the leader of a resistance among the Iron fey themselves, seeks her out. His people will not serve the king who took Machina's crown, whom they call a usurper, and they hold that the crown was never his to take. Glitch brings Meghan to a hidden sanctuary and puts an argument to her that she does not want to hear.

The false king's realm is expanding far faster than Machina's ever did, and the iron creeping into the wyldwood is killing Faery outright rather than merely poisoning it. Meghan decides to stop being someone who has to be rescued. Ash trains her to fight in earnest, and she works at both kinds of glamour she carries, the Summer power inherited from Oberon and the iron glamour no other fey can survive, let alone use. Puck catches up with them and the unresolved three-cornered tension between the three of them resumes where it left off. Ash then does something that cannot be undone: he swears himself to Meghan as her knight, a formal and binding oath of service and protection that puts her above his court, his exile and his own life.

Oberon and Mab summon the exiles they threw out. Faery is losing ground to the Iron Realm, and both monarchs have privately stopped pretending otherwise, though neither will say so where the other courts can hear it. Their offer is a bargain: Meghan is the only creature who can walk into the Iron Realm and survive, so she is to go and kill the false king, and in exchange her exile and Ash's will be lifted. It is not phrased as a request. Meghan agrees and sets out for the Iron Realm with Ash, Puck and Grimalkin, with Glitch's rebels for allies. On the way they meet the traitor knight, Rowan, Ash's own brother, who sold Winter to the Iron fey and is still serving them.

Inside the Iron Realm the party crosses country that is actively hostile to everything Ash and Puck are: the iron in the air weakens them by the hour, and Meghan can only slow it down. They pass through the ruins of Machina's old territory, left to rot since his death, and seek out a clockmaker who has survived every change of rule and knows more about the Iron crown than anyone living. A gremlin named Razor attaches himself to the party and cannot be shaken off. Meghan learns what the crown really is: not an ornament but the realm's power itself, held by whoever is strong enough to carry it, which is why the false king wears it and why Machina's death left it loose in the first place.

The realm's history comes out. Ferrum, the Iron Realm's first king, ruled before Machina deposed him, and he did not die when he lost the throne. Rowan puts a proposal of his own to Meghan. The fighting inside the realm becomes Iron against Iron as Glitch's rebels move openly against the king's forces. Meghan works out what killing the false king would actually require of her, and what it would cost afterwards, which is the part nobody who sent her has been willing to discuss. She and Ash spend the last night before the battle together, both of them aware that the bargain with Oberon and Mab contains no promise that she survives it.

The Iron fey advance on Faery and the courts of Summer and Winter meet them in open battle. Meghan reaches the false king and destroys him, and the Iron Realm's power, the crown itself, is left with nowhere to go. Left loose it will keep expanding and keep killing Faery, and Meghan is the only being who can take it and live. She takes it. Becoming the Iron Queen makes the Iron Realm her home and her responsibility: she cannot leave it, and nothing that is not iron-touched can survive inside it for long. That includes Ash, who is already failing from the exposure and will not leave voluntarily. Meghan uses the one authority he cannot refuse, ordering her sworn knight out of her realm to save his life. She also gives up the mortal life she had been fighting to get back to, and her family with it. The book ends with Meghan crowned in the Iron Realm and Ash outside it, released from her service and refusing to accept that the parting is permanent.

Meghan destroys the false Iron King in the battle for Faery, and then makes the choice the whole book has been driving toward. The Iron Realm's power has to be held by someone or it will go on consuming the Nevernever, and she is the only creature alive who can hold it without being destroyed by it. She takes the crown and becomes the Iron Queen, which means remaining in a realm no unaltered fey can enter and survive. That includes Ash, who is already dying of iron exposure and refuses to leave her, so Meghan uses the one authority he cannot argue with: she is his queen and he is her sworn knight, and she orders him out of her territory, releasing him from her service rather than watch him die in it. She also loses the human life she had spent three books trying to get back to, leaving her mother, her stepfather and Ethan behind for good. The war with the Iron fey ends, Faery survives, and Meghan becomes a third monarch the old courts have to acknowledge. Ash leaves the Iron Realm alive and entirely unwilling to accept the arrangement. In the closing pages he sets out to find a way to become something that can live in iron, by earning a mortal soul, which is the journey the next book follows.