The Raven at the Ash Door by K.A Linde

Here is a summary with spoilers for The Raven at the Ash Door by K.A Linde

Kierse, a half-Fae thief with newly awakened and unstable magical abilities, joins a team (which includes her boyfriend, Graves) attempting to steal the legendary Stone of Fal from the vault of a Scottish warlock in Edinburgh. Her mission is complicated by the magical bond that ties her to Lorcan, a powerful Druid who bound her magic in the past without her consent. During the heist, Kierse's developing abilities include magical intuition, light manipulation, and absorption magic. The operation fails when the group discovers the Stone of Fal in the vault is a fake, leaving the true artifact still missing. During their escape, Kierse accidentally kills the warlock Archie when her absorption magic activates unexpectedly, thus forcing the group to conceal the death to avoid reigniting a conflict between Fae and warlocks. Her magic activated like that due to Lorcan unexpectedly showing up. It pisses Kierse off that he shows up, and now she even feels more guilty about the death of the warlock.

While fighting, all three receive assistance from Bram, an old family friend connected to Kierse's deceased parents, whose murder by the mysterious Fae Killer continues to influence her actions. Bram helps them bury Archie's body while revealing more about Kierse's family history. At the same time, the magical bond between Kierse and Lorcan remains unresolved, creating tension with Graves, who is still madly in love with Kierse and insanely jealous that she has a bond with Lorcan. Once the body is buried, the group continues searching for a way to break the bond and trying to find out where the real Stone of Fal is.

Later, Kierse trains under Kingston, Graves's former mentor, who teaches Kierse advanced magical skills such as creating portals. The only time she has been able to create one is when she was with Lorcan. Although the training expands her abilities, it also demonstrates the dangers of her uncontrolled magic, including a near-fatal portal accident on the London Underground. In a POV chapter of Kingston, he returns home one day to learn that Archie's body was found dead and recently buried; he suspects it to be Kierse's doing, and that maybe she has some more powers she isn't telling him.

Also during this period, the group discovers the Ash Door, a magical doorway connected to a sacred tree and Kierse's triskel mark. The appearance of the door suggests a deeper connection between Kierse and the magical realm of Faerie, although its full purpose remains unknown; though it does seem to have a draw to Kierse, and it does speak to her. The bond between Lorcan and Kierse is also still there, and Lorcan likes to linger in Kierse's head. She makes him agree on a bargain: he has to leave her head if she is not in danger. Lorcan agrees, which then gives Kierse and Graves a chance to actually be intimate, something they haven't been able to do since the bond was created.

Meanwhile, investigations into the Fae Killer continue, leading the group to Las Vegas, where they question witnesses and consult the powerful witch Rosetta. She does a tarot reading for Graves and tells him that he is going to have difficult choices and personal loss soon. Rosetta does tell them to be wary of Amberdash, Kierse's old boss. This comment makes Graves and Kierse feel like they are constantly one step behind him.

The investigation eventually uncovers that Kingston is the Fae Killer, revealing that Graves's trusted mentor has been responsible for a series of murders motivated by ancient grievances. The revelation forces the group to confront Kingston, who is ultimately killed by Lorcan.

Despite this victory, the larger conflict escalates when Amberdash, leader of the Men of Valor, hosts a monster gala that serves as the backdrop for another attempt to obtain the Stone of Fal. Only Kierse is invited to the party, though upon arrival, Lorcan is there to be with her. Kierse successfully steals a ledger in Amberdash's office, though in the process she is caught, as is Graves, who sneaks in. Amberdash brings Graves out to use as an example and starts to humiliate him in front of his party. Amberdash basically says he is going to be the new mayor, and anyone who wants out can leave. Almost no one leaves, meaning no one is supporting Graves now. Lorcan grabs Kierse to save her, leaving Graves to get out on his own.

Kierse is upset with Lorcan for making her leave Graves behind, and they have a fight about it. When Graves does manage to get out, the two have a discussion. Graves uses his magic and is able to tell how Kierse really feels about him. Kierse has to admit that, thanks to the bond, there is something there with Lorcan, though she doesn't want there to be. Graves hates it and tells her to leave. For the next few days, Kierse is incredibly sad and misses Graves. After a few days of self-pity, Lorcan shows up to comfort her. She spends the night there, but she tells him absolutely nothing will happen between the two.

The next day, she tells Lorcan that she is going to go after the Stone so she can break the bond with him. On her way there, she is intercepted by Jason, her old tormentor. There is a massive fight. He traps her, torments her, puts magic cuffs on her, and it is pure hell for her. In the process, Jason reveals that the real Fae Killer is still alive; it is Amberdash. With that new information, Kierse is full of rage and manages to fight back and kill Jason. Lorcan is able to pinpoint where Kierse was and grabs Graves to come help save her. Kierse is out for a few days, and when she wakes up, she and Graves make up.

With the group all back together, they decide to continue their heist to get the Stone. Though the rest of the group who have been put in place in Amberdash's life have all been found out, their plan comes crumbling down. They decide to change their plan and make it look like they don't know they have been caught. Their plan goes perfectly, and Kierse is still able to find the Stone, hand it off to her friend, and make it look like she didn't even do it. Though when they leave the gala, they find out that the Stone never made it to their car. Kierse knows that Lorcan has it, knowing that she wants to break the bond. They go to Lorcan, who happens to be near the Ash Door.

As the struggle for the Stone intensifies, Kierse attempts to draw upon the power of the Ash Door and Faerie itself. The immense magical energy overwhelms her, causing catastrophic burnout that nearly kills her. Graves sacrifices his own life to save her, ultimately killing himself. This forces Kierse to make a desperate bargain to restore him. Using the Stone of Fal, she enters into a magical bargain with Lorcan, agreeing to leave with him and surrender her memories and love for Graves in exchange for Graves's resurrection. The binding promise rewrites reality, erasing Kierse's memories of their relationship while leaving only Graves and Lorcan aware of what truly happened.

Following the bargain, Graves is restored to life, but Kierse now believes Lorcan is her destined soulmate and no longer remembers her love for Graves. As she begins a new life under the effects of the magical bargain, Graves commits himself to finding a way to break the curse and restore her memories. At the same time, the Monster Treaty collapses after a decisive vote, ending the fragile peace between magical factions and creating widespread political instability.