Emily Wilde's Map of the Otherlands recap

Back at Cambridge with her encyclopaedia published, Emily Wilde takes on a new problem: Wendell Bambleby, now openly an exiled faerie king, cannot return to his own realm, his stepmother's agents can still reach him, and the exile is doing him real harm. Emily's answer is research. She begins reconstructing the work of Danielle de Grey, a dryadologist who vanished decades earlier while studying the doors between worlds, on the theory that de Grey's lost map could locate a way into Wendell's kingdom. The search takes Emily, Wendell, her niece Ariadne and the sceptical senior scholar Farris Rose into the Austrian Alps, to a village living under severe rules alongside its own Folk. The expedition is attacked, Wendell's health fails, and Emily crosses into faerie territory in pursuit of de Grey's route. She finds de Grey herself, still alive inside a faerie realm, and with what she knows the door becomes findable. Wendell reclaims his throne, but his stepmother has poisoned the land, which is dying. Emily accepts his proposal and stays.

Previously: Emily Wilde, a Cambridge dryadologist, spent the winter of 1909 in Hrafnsvik, a remote village in the northern country of Ljosland, gathering the last material for her encyclopaedia of faeries. Socially disastrous and academically formidable, she won the village over slowly, cultivated a small local faerie named Poe as a source, and got closer to Ljosland's courtly Folk than any scholar before her. Her Cambridge rival Wendell Bambleby followed her there uninvited, and she confirmed what she had long suspected: he is not human but an exiled faerie king, driven from his own realm by his stepmother, who holds it and wants him dead. Emily dealt with the Folk who had been taking people from the village and recovered those they had taken, and her encyclopaedia was completed. Wendell, no longer hiding what he is, asked her to marry him; she gave no answer, and the proposal was left standing. They returned to Cambridge with his exile unresolved, which is where this book begins.

Emily is back at Cambridge with her encyclopaedia published and her reputation made, and finds academic life no easier for it. Her niece Ariadne joins her as an assistant, ambitious and entirely undeterred by her aunt's manner, and Poe, the faerie from Hrafnsvik, has attached himself to the household. Wendell's proposal remains unanswered, and his situation is worse than he is willing to admit: he cannot return to his own realm, his stepmother's people can still reach him in the mortal world, and being severed from his kingdom is doing him harm. Emily's response is characteristically scholarly. She begins reconstructing the work of Danielle de Grey, a dryadologist of the previous generation who disappeared while investigating the doors between the worlds, on the theory that de Grey's lost map could locate a way into Wendell's realm.

The search takes Emily, Wendell and Ariadne out of Cambridge and into the Austrian Alps, to a mountain village that lives alongside its own local Folk under its own severe set of rules, and where de Grey was last known to have worked. Farris Rose, a senior dryadologist deeply sceptical of Emily's conclusions and of Wendell personally, attaches himself to the expedition. The mountain Folk prove less accommodating than the ones Emily studied in Ljosland, and the villagers' precautions are correspondingly strict. Emily works through de Grey's surviving notes and the local tales in parallel, on the principle that a door will be described in a story long before anyone writes a paper about it.

The work becomes dangerous. The party is attacked, and it becomes clear that the mountains are not the only threat: Wendell's stepmother's interest has followed them, and there is faerie attention on what Emily is trying to find that has nothing to do with scholarship. Wendell's condition deteriorates, and Emily has to face the fact that his exile is not merely a political inconvenience but something that is killing him. She and Ariadne cross into faerie territory in pursuit of de Grey's route, where distance and time behave by their own rules, and Emily's method of reading the Folk through their stories is what keeps them alive there.

Emily establishes what became of Danielle de Grey. She did not simply die in the mountains: Emily finds her alive inside a faerie realm where the ordinary passage of time does not apply, decades after she disappeared. What de Grey knows about the doors between the worlds is the missing piece of Emily's reconstruction, and with it the location of a way into Wendell's realm stops being a rumour and becomes a solvable problem. The expedition turns from research into a race, since Wendell is failing and his stepmother's people have every reason to reach the door first.

Emily finds the door and the party goes through into Wendell's realm. Wendell takes back his throne and breaks his stepmother's hold on the kingdom, but the victory is immediately spoiled: she has poisoned the land itself, and the realm is sick and dying in a way that reclaiming it does not remedy, which means Wendell is too, since a faerie king and his kingdom are not separable things. Emily, having spent two books declining to answer him, accepts his proposal and the position that comes with it. The book closes with her living in a faerie kingdom rather than in Cambridge, and with her scholarship redirected at a problem no dryadologist has ever had access to: how to heal a poisoned faerie realm.

Emily finds the door, and the party reaches Wendell's realm. Wendell takes back his throne and his stepmother's hold on the kingdom is broken, but the victory is spoiled at once: she has poisoned the land itself, and the realm is sick and dying in a way that simply reclaiming it does not fix. Because a faerie king and his kingdom are not separable things, that sickness is also Wendell's, so the problem he spent two books trying to solve turns out to have been the easy half. Emily, who has spent two books declining to answer him, accepts his proposal and with it the position that comes attached to it. Danielle de Grey's fate is settled and her work is finally in the hands of someone able to use it, and Ariadne has her fieldwork and rather more of it than she bargained for. Farris Rose's objections have been overtaken by events. The book closes with Emily in a faerie kingdom rather than in Cambridge, no longer a visiting scholar of the Folk but a resident of their world with a title, and with her scholarship pointed at a problem no dryadologist has ever had access to: how to heal a poisoned faerie realm before it takes its king with it.