Alone with Gen in her bedroom, Kierse explains that Graves stalked her in Paris and manipulated her into a plan to steal the magical Spear of Lugh (in the previous book). She puts on her wren necklace, a family heirloom that first drew Graves’s attention to her. When Gen asks whether they slept together, Kierse denies this but admits that things are heated between them.

Kierse retrieves the spear from a heavily warded case hidden under her bed. The sentient weapon mentally communicates with her, asking who it can kill. Gen is unnerved by the spear, and Kierse reluctantly agrees that it’s too dangerous to bring into the market. They briefly discuss their friend Ethan, who’s training with the Druids. They conclude that Lorcan is deliberately keeping him from contacting them.

Their conversation is interrupted by Niamh, a woman they befriended in Dublin. Graves is instantly hostile and identifies her as “the robin,” the magical counterpart to Kierse, the “wren” who replenishes Graves’s magic. He explains that Niamh is aligned with his enemy, Lorcan, just as Kierse is aligned with him, the Holly King. Niamh admits that Lorcan sent her to spy on Kierse but insists that her friendship with them is genuine and that she hasn’t been reporting to him. She’s also revealed to be a High Priestess who has been covertly training Gen. To prove her loyalty, Niamh suggests that they visit a bookstore owner named Oisín, who she says will vouch for her. When Niamh asks what task Kierse is set on, Graves mentions the plan to go to the goblin market.

The group goes to a small bookstore on Grafton Street that serves as the entrance to the goblin market. The elderly owner, Oisín, greets Graves by his first name, Brannon. It’s revealed that Oisín is the man from a famous Irish faerie tale who was cursed with agelessness after a stay in the fae realm. Kierse explains that she’s entering the market to find a cure for her jumbled, nightmarish memories of her parents. Oisín, Graves, and Niamh all try to dissuade her. Graves suggests a visit to the Covenant, a group of “witch doctors,” as an alternative since Kierse won’t work with him directly and Druid involvement isn’t safe. Determined to get answers about her family and her nearly extinct race, Kierse insists on entering the market that night. Graves reluctantly agrees to go with her.

At the back entrance to Nying Market, Kierse and Graves prepare to enter. They’re joined by Niamh, who has also secured a coin for entry. The main currency for admission is the consumption of highly addictive goblin fruit. Kierse, however, barters for her entry using the bracelet she stole from the Queen of Versailles. The goblin guard, Fraan, had originally asked for the bracelet as a joke but enforces it anyway. He frames Kierse as a cheat under the goblin code when she tries to renegotiate, so she gives him the bracelet to avoid drawing the attention of armed goblin guards. With their entry secured, the trio steps into the market.

Nying Market is dark, filthy, and teeming with monsters. To find a cure for Kierse’s memory loss, they must locate an information broker known as a bookkeeper. Graves leads them to the shop of a bookkeeper named Rio only to find it destroyed. Graves lists seven market entrances in different cities; Niamh explains that they’re connected like spokes on a wheel. To find Rio, they must ascend to another level.

At a guarded stairway, goblins demand that they eat goblin fruit to pass. A fight ensues, and the trio defeats the guards, fleeing up the stairs with reinforcements in pursuit. They emerge into the New York City section of the market, where Kierse feels a pang of homesickness. The goblins catch up, sparking a chase that ends with the group hiding in a locked room behind a theater stage. Graves tells them that he has a contact who can help them.

Graves leads them to a pub called Ye Olde Pilgrim to meet his contact, a mercenary named Vale. Before Vale arrives, a bounty hunter confronts Graves, revealing that a 2,000,000-mark bounty has been placed on him. A brawl breaks out, and Graves uses his mind magic on the bounty hunter. The hunter’s minions then block the exit, and in the ensuing melee, Kierse is stabbed in the ribs by a goblin. Just as she’s about to collapse, Vale appears, kills her attacker, and helps Graves carry her to safety.

Kierse awakens in Vale’s safe house as Niamh uses her High Priestess healing abilities to mend her wound. Graves, furious that she was nearly killed, urges her to abandon the mission, but Kierse refuses. Once recovered, she meets the charismatic Vale, who’s surrounded by an impressive collection of weapons. Having been promised a set of armor by Graves as payment, Vale leads the group to Rio’s shop on the New York level of the market.

The group arrives at Rio’s shop. Rio recognizes Graves and Niamh from past dealings, which are recorded in their ledger. When Kierse requests information on restoring memories, Rio demands a vial of her blood for payment, which would reveal her identity as a wisp. Graves and Niamh refuse. As an alternative, Rio proposes a game: Kierse must truthfully answer three questions. Kierse answers the first two, stating her name and that the nature of her magic is absorption. For the final question, Rio asks what kind of monster she is. Rio clearly already knows the answer, and lying would force her to give blood, so Kierse whispers that she’s a wisp. Having confirmed this dangerous secret, Rio provides an address for Rizz’s Oddities in the market’s Shanghai section.

To reach the Shanghai level, the group takes a dangerously overcrowded elevator. Inside, a human high on goblin fruit accosts Kierse, smearing juice on her face. Terrified of ingesting the substance, she panics until Graves calms her and cleans it off. They emerge into the Shanghai market, a bright, futuristic cityscape. They locate Rizz’s Oddities, a small shop run by Rio’s sibling Rizz. He sells them three potions to restore memories, a “smoother,” an “intent” potion, and the memory potion itself. Niamh verifies their magical authenticity, and Graves pays the high price without negotiation.

Back at the apartment, Gen’s tarot reading indicates that Graves must act as a magical “anchor” for Kierse while she takes the potions. In her bedroom, Kierse focuses her intent on remembering who her parents were, and Graves holds her magic to keep her safe. The potions transport her into a memory of a small apartment where she sees her younger self with her parents, Shannon and Adair. Kierse is shocked to see her mother alive, as she had always believed she died in childbirth. Her parents are on the run from a “Fae Killer.”

The memory shifts to Graves’s New York brownstone, where her parents have come seeking help. Graves recognizes Shannon as a wisp. Adair trades a Fae-blessed knife for information: Graves names Cillian Ryan, a rogue Druid, as someone who has the hiding spell they need since they can’t go to Lorcan. Graves gives them an amulet to trade for the spell casting before the memory ends.

Oisín reflects on the Fae curse that separates him from his wife, Niamh. He recalls first meeting Brannon Graves centuries ago. A young man who arrived in Ireland from England, Graves initially claimed to be searching for his mother’s people but eventually confessed to Oisín that he was seeking Druids. Oisín arranged a meeting between Graves and Lorcan, an act he now considers both a great victory and a deep regret. Back in the present, Oisín decides to meddle once more and makes an international phone call to Lorcan. He tells Lorcan that Graves is present and that they will be joining him shortly. After the call, Oisín reaffirms his motivation to do anything necessary to restore the Fae and reunite with Niamh, even if it means betraying Kierse’s trust.