The Iron Knight recap

Told from Ash's point of view. Exiled from Winter and ordered out of the Iron Realm by Meghan so that its iron would not kill him, Ash sets out to gain a mortal soul, the one thing that would let him live at her side. Puck comes along uninvited, Grimalkin guides them at his usual price, and the Big Bad Wolf follows for reasons of his own. On the road they are joined by Ariella, Ash's first love, whose death long ago began his feud with Puck, alive and unwilling to explain how. They reach the end of the world, where a Guardian sets the trials that decide whether a fey may be given a soul. Ash is made to face everything he has done as Mab's weapon, and is finally offered an entire happy life in which Ariella never died and Meghan does not exist. He refuses it. The price of the soul is a life, and Ariella gives hers, saying she was kept alive for exactly this. Ash is remade with a mortal soul, no longer vulnerable to iron, his feud with Puck ended rather than settled. He crosses into the Iron Realm and reaches Meghan for good.

Previously, and told this time from Ash's point of view. Meghan Chase, the half-human daughter of Oberon of the Summer Court, was drawn into Faery when Iron fey, a new breed born of human belief in machines and lethal to ordinary fey, stole her little brother. She destroyed their king Machina, was held afterwards in the Winter Court under a bargain with Ash, Mab's youngest son, and fell in love with him. When Iron fey stole the Scepter of the Seasons and set the courts at war, Meghan recovered it and stopped the fighting by wielding iron glamour openly; Oberon banished her for it, and Ash was cast out of Winter for choosing her. In exile the two of them were sent back into the Iron Realm to kill the usurper wearing Machina's crown. Meghan killed him, and then, because the realm's power had to be held by someone or it would go on devouring Faery and she was the only one who could hold it, she took the crown herself and became the Iron Queen. That bound her to a realm whose iron kills any ordinary fey. Ash, her sworn knight and already dying of the exposure, was ordered out of her territory by his own queen so that he would live. Meghan gave up her human family and her mortal life along with him. Ash left the Iron Realm alive, exiled from Winter, unable to return to the one person he wants, and determined to change that.

Ash's answer is the one thing no fey has: a mortal soul. With one he could survive the Iron Realm and stand beside Meghan; without one he cannot cross her borders and live. The difficulty is that nobody in Faery can tell him it has ever been done. Puck invites himself along, which Ash tolerates because Puck is useful and because the blood feud between them, sworn over Ariella's death long ago, is a debt neither of them intends to settle while Meghan needs them both alive. Grimalkin turns up to guide them at his usual price. They travel out into the deep wyldwood, far past any territory the courts hold, and acquire an unwanted companion in the Big Bad Wolf, an enormous fey made out of every retelling of the story, who is entirely honest about being a predator and about wanting to see how Ash's journey ends.

The road runs through country with no interest in whether they survive it, and the answers they collect are consistent: what Ash wants can be granted only at the end of the world, by a guardian who sets trials, and the price is something nobody will name in advance. A hooded stranger joins the party, and she is not a stranger. Ariella, the Winter girl Ash loved and watched die years ago, the death he has blamed Puck for ever since, is alive, unchanged and travelling with them. She says she was taken out of her death and kept away from the world for a reason she is not yet willing to give. Her presence takes apart the one certainty Ash's last several centuries have been built on, and it puts Puck in an impossible position.

The party crosses out of the known world entirely, past anything mapped, and reaches the place where the trials are held. The Guardian there is neither hostile nor kind: it simply requires that a fey asking to be given a soul be shown, precisely, what he already is. The tests begin with Ash's own history. He has been Mab's son and Mab's weapon for a very long time and has killed a great many people in that service, and the trials make him meet what he did rather than remember it from a distance. There is no version of the account in which he was not responsible.

The trials continue past the point where Ash's companions can follow him. The last of them is not a fight but an offer: an entire life in which Ariella never died, in which the hunt went differently and the centuries since were happy ones. It is convincing, it costs nothing to accept, and accepting it means Meghan is not in it. Ash refuses and comes out the other side, which the Guardian treats as the answer it was looking for. What remains is the price, and by this point it is clear that the price is a life.

The soul cannot be granted without a life given for it, and Ariella gives hers. She tells Ash she was kept alive precisely for this, that she had already seen it and came back for no other reason, and she goes willingly and over his objection. Ash is remade: he keeps himself, but with a mortal soul and a mortal's vulnerability, and iron can no longer destroy him. Whatever lies between him and Puck over Ariella is not repaid, but it is finished, and the feud ends without a killing. Ash leaves the end of the world, crosses into the Iron Realm that would have killed him before, and walks into Meghan's court to stay. The quartet closes with the two of them together in the realm she gave up everything else to hold.

Ash passes the Guardian's trials at the end of the world, the last of them a temptation rather than a fight: an entire life in which Ariella never died and Meghan has no part in it, which he refuses. The soul he is asking for requires a life given in exchange, and Ariella gives hers, telling him she had already seen it and was kept alive for no other purpose. Ash is remade with a mortal soul, still himself but finite and vulnerable, and no longer destroyed by iron. The blood feud between Ash and Puck, which began with Ariella's first death and which Ash had sworn to end in a killing, is closed by her second; the two part alive and no longer sworn enemies, on terms neither of them says out loud. Grimalkin departs with his favours uncollected, as he generally does. Ash leaves the end of the world, crosses the border that would have killed him before, and reaches the Iron Realm and Meghan's court, where he can now stay. The original quartet closes with Meghan established as the Iron Queen and Ash beside her, the Iron Realm accepted as a third power in Faery, and Meghan's human family left behind in the mortal world.