Seven years ago. Tirnanese Highlands - Kingdom of Anoun. A fleet of Burguish soldiers lead by Philo, Darius, and Winshaw approach a faerie kingdom. They are greeted by Mima Roosan and an entire community of faeries. Per the terms of the Tain Treaty, they’ve come to commandeer the kingdom for use in defense of their lands.
Winshaw orders Philo and Darius to search the buildings and grounds to check for hiding, places, traps, weapons, or anything that could present a danger. Philo begins his search from the ground, starting outside the kingdom’s walls. He notices that a set of tracks in the snow mysteriously stop. He looks up to see a cave entrance and decides to check it out. What he finds is the kingdom’s library, though he is attacked by Vignette almost immediately after. She holds a blade to his throat and explains that he’s trespassing. She worries that he’ll report the library to his commander, but Philo insists that’s not his intention. So, she reluctantly lets him go.
Philo reports back to Darius. Neither have anything to share. Just above, Mima Roosan questions if Philo will keep his word about not telling anyone about the library. Vignette isn’t sure, claiming he’s "faan-troigh", and you can never be certain with their kind. From here on out, Vignette will be keeping a close eye on Philo.
Darius returns to inform the camp that the telegraph line that connects them to High Bresail is down. It snapped over the ravine. Philo wants to put together a repair detachment. However, the ravine was too wide. While they didn’t have any equipment capable of such lengths, a fae could run the line and Philo has Vignette in mind.
Vignette flies the line across the ravine from Darius to Philo. After successfully relaying the line, Vignette decides to stay to watch them finish the job. In that time, Philo gives her a book he’d been reading, Kingdoms of the Moon. It’s about a rogue inventor who journeys to the moon and falls in love with the princess of a lunar tribe. Vignette mocks the book for its insane premise, though Philo would beg to differ and insists that she take the book to read for herself.
Unbeknownst to the group, three Pact soldiers who’ve infected themselves with the wolf’s curse watch them from afar. They get undressed and inject themselves with some kind of catalyst to induce the change into wolf-like beasts known as Marroks. An echoing howl alerts Philo and his men of their presence. He warns Vignette to stay put as he heads over to the other side. By the time he reaches the other end, several of his men are dead. They’ve been ripped apart. A Marrock charges at Philo. He kills one before being attacked by another. Fortunately, Vignette comes to his rescue and kills the beast. They are joined by Darius soon thereafter. He ran the last remaining Marrock down and killed it.
Philo and Darius report back to Winshaw with the discovery that the Pact had been infecting their own men with the wolf’s curse.
Vignette joins Philo as he sits on a cliff. She finished the book he gave her. It was extraordinary. By the end, she was sobbing. Philo tells her to keep it. In exchange for his kindness, she offers to show him around the library.
It’s the largest library in the Kingdom of Anoun. There are possibly thousands of books within it, though no one has ever counted. Holy texts, maps, scientific research. Histories going all the way back to the Queen of the Crows. She shows him one book in particular. A 700-year-old manuscript. It tells the tale of the first human in Tirnanoc. He was an explorer called Isen who’d washed ashore after a storm, and was taken to Queen Aradis, who became utterly fascinated by him. He stayed as a guest of her court for quite a while, and they fell desperately in love. Sadly Isen yearned for home. So, he built a ship and left. No one knows if he returned, but he did leave something of himself behind. They had a child. A half-blood son. He spent his life searching for his father. Philo remarks how it sounds rather like his book that he gave Vignette. She agrees, and speculates that maybe Isen did find his way home and brought the story with him. Philo thinks that maybe the writer of his book heard the tale as a child from his faerish nanny. Vignette likes the idea that a story like that might cross the world and somehow finds its way back centuries later, changed by constant retelling, but familiar, as if to tell them that they’re not so different in the end.
Mima Roosan and Winshaw get word that Fort Sovereign were hit by the Pact. They’d been advancing further everyday. Many are wounded. They’ll need blood. All types. They’re quite a distance away. While fae blood may be of no help to the wounded soldiers, they can at least fly the blood over. They could have relief there within hours. With that, Winshaw orders every able-bodied man to the front to donate blood. For reasons unknown, Philo runs away from the kingdom. He takes shelter in a cave as the rain comes pouring down. Unbeknownst to him, Vignette has also taken shelter in the cave. They come upon one another and proceed to have sex. Vignette’s wings glow a bright luminescent blue.
Quite a bit of time has passed, and Vignette and Philo remain together. She explains to him the meaning behind each braid in her hair. One represents her surname, Stonemoss. Another for the year she was born. And another is the one in which a woman gives away when she gives her heart. Vignette notices the scars Philo's back. He explains that they’re from a childhood injury. However, he was too young to remember how. All he knows is that the headmaster said it was how he turned up at the Foundling Home.
Philo asks Ivos if he’s alright, to which he responds that while it may sound mad, he thinks he can still feel his left leg, which he no longer has. Winshaw then asks Philo’s opinion of the fae. Philo believes they’re an interesting people. They’ve been around for so much longer than humans, for a start. Philo spots Darius sneaking out the kingdom in the darkness of the night. He follows Darius who runs into the nearby woods and turns into a Marrock as the full moon shines in the sky. As it turns out, Darius was bitten when they were attacked by the Pact.
The following morning, he awakens in blood, next to a deer he had slaughtered. As he cleans himself off in the river, Philo throws him his clothes. Darius explains that he’s got it under control. It’s only once a month, and he’s got a whole forest to get himself lost in. However, when he gets back to the Burgue, he’ll hand himself in. He worries what they’ll do to him as he’s now a Critch that could turn them into a Critch. Darius isn’t the only one with a secret though. He knows about Philo’s relationship with Vignette. He can smell it. The wolf fades slowly, he remarks. Darius looks forward to the change. In the moment when the wolf comes out, it’s freedom. It’s like the wolf is what you were all along underneath it all and the bite was just permission to stop pretending.
A group of fae refugees suddenly arrive at the kingdom. Tourmaline is among them. She explains they were attacked. Kish has fallen. As Tourmaline takes a bath, she shares with Vignette just how troubled she’s been. They waited to start shelling until they could surround the city with sharpshooters. Once it began, when they tried to get away, the Pact started picking them right out of the air. The Pact are awful, but Tourmaline thinks no better of the Burguish. They’re Imperialist shites, as far as she’s concerned. Tourmaline saw her whole life in flames and all she could think is that she had to get to Vignette, who explains that she’s met someone. Tourmaline regrets how things ended between them. But for Vignette, it never ended. Only changed. Tourmaline is still her closest friend. Tourmaline asks who it is. She was surprised to learn it was a Burguish soldier. She warns Vignette that it won’t end well. Once the war is over, he’ll leave and start a family of his own. Vignette insists that Tourmaline is wrong.
Vignette and Philo have sex, though her wings don't brighten, which doesn’t go unnoticed by Philo. She responds that it’s not supposed to happen with faan-troigh anyways. What Tourmaline said has resonated with Vignette, so she asks Philo what will happen to them once the war is over. He hadn’t thought that far ahead, but he insists that she’s not just an exotic fuck. She’s like coming home. Philo lost a part of himself a long time ago. He tried to forget and ignore it, but it was always there. The scars on Philo’s back are from when his wings were sheared. He’s a half-blood. He’s felt his wings his entire life despite not having them.
Philo never knew his parents, so he always wondered what their story was. An affair. A drunken collision. Whether they loved each other or loved him. Philo does however at least understand their reason for shearing him. Life in the Burgue is hard enough for fae. Half-bloods don’t belong anywhere. They thought if they could pass Philo for human then he’d have a better life. The headmaster knew what he was. He kept Philo’s secret. He told him to hide it and stay clear of doctors to prevent them from discovering he has fae blood. Being with Vignette at the kingdom is the closest he’s ever felt to home.
Tourmaline and the other refugees plan to leave the kingdom. They’re headed down the coast to Mag Mor. It’s the biggest shithole in Tirnanoc, but there’s nothing much to fight over, so she’ll be safe there. She invites Vignette to come along, but she declines, though not without giving Tourmaline one last hug.
Before leaving, Tourmaline asks if Philo loves Vignette because she loves him, and it’s going to get her killed. Tourmaline has seen what’s coming. The Burgue is losing the war and the kingdom will be Pact territory soon. And Vignette will stay by Philo’s side even when he begs her to fly away and save herself because that’s who she is. She’ll die for Philo. If he loves Vignette, then Tourmaline tells him to break it off so that Vignette doesn’t end up dead.
Philo, Darius, Winshaw, and Mima Roosan learn that the Pact have taken the capital. The whole front had collapsed, forcing them to evacuate. The Republic of the Burgue are going home, much to Philo’s dismay.
As they evacuate, Mima Roosan instructs Vignette to seal the library. Philo follows Vignette and tell her to leave with the others. He’ll meet her at Port Moradoon, but she worries they won’t and doesn’t want to leave Philo behind. She’s determined that they leave together. Before heading off to seal the library, she gives Philo her braid for when a women gives her heart away. They’re to meet in the Garden of Stones. They express their love for one another before parting ways.
Philo returns to the kingdom to inform everyone of the incoming Pact airships. Meanwhile, Vignette does her job by sealing the library. She puts a key inside a lock and turns it, which in turn buries the library within the cave.
As the Pact airships approach, they shoot the Wing Brigade out the sky and then begin attacking the kingdom directly, bombing the land, killing many. Philo approaches Mima Roosan and asks her to lie and tell Vignette that he was killed in the attack. Vignette collapse to the ground at word of Philo’s demise. She’s distraught. As Philo and Darius lead their men to safety, Vignette attempts to return to her fallen kingdom in search of him, but Nefrie and Mima Roosan fly her away to safety.
Present day, Philo stands outside the Tetterby Hotel, in the rain, hoping to speak to Vignette. She comes down to talk to him. He’s scared as she threatened to reveal his secret. Vignette reasons that she was angry, but she never intended to tell anyone that he is a half-blood. While she’s still hurt after he left her, she’d never expose him. Philo didn’t want her to die for him. That’s why he had Mima Roosan lie to her. However, Vignette has spent the last seven years wishing she had died. Philo was her hope and together they could’ve had a life. However, Philo doubts it would’ve worked. No matter what, Vignette always accepted Philo for what he is. Seeing just how lost he is now, Vignette will say a prayer that he finds where he belongs, but she knows it’s not with her.