The Night Prince by Lauren Palphreyman

Here is a summary with spoilers for The Night Prince by Lauren Palphreyman

Aurora remains at Lowfell Castle after the events of the previous book, recovering from James's bite and learning to live with the forced life bond Blake created between them. Once fully awake, Aurora goes to Callum to tell him all of Blakes plans, which really messes up Callum’s plans now that the two are bonded. Meanwhile, Aurora suffers repeated fevers caused by her dormant wolf nature and unknowingly sleepwalks to Blake's room with the intent to kill him. The bond the two share also have brought their dreams together. Through shared dreams, Blake reveals fragments of Night's prison and his own childhood imprisonment beneath the Southlands palace, where he was tortured as a child. 

James takes Fiona hostage and demands Aurora's return under wolf law because his bite marks her as his property. During a gathering of the wolf clans at Dawn's Craig, Blake publicly bites Aurora in front of the assembled wolves, making her a member of his clan and preventing James from claiming her. The act further damages Blake's relationship with Callum, who nearly kills Blake before realizing Aurora suffers every injury inflicted on him because of their shared life bond. Aurora also learns more about Blake's past through Elsie, his half sister, discovering that he killed their abusive father after rescuing Elsie from being sacrificed to Night and that he has spent years protecting abused and abandoned people. On top of this, the new bite that Blake gave her has put another barrier up between her and Callum. 

Aurora continues struggling with the transformation everyone expects to happen, but despite repeated fevers she never shifts into a wolf. Blake eventually tells her the truth that she cannot be human because the life bond he created only works between wolves, although he cannot explain why her transformation has not occurred. Ian betrays Lochlan's clan by kidnapping Aurora and delivering her to James and the allied alphas. James forces Blake to kiss Aurora in front of Callum to prove Blake's true feelings, but Blake uses the distraction to free her and escape as Alexander's soldiers attack the manor. Blake is shot with wolfsbane-coated bullets while protecting Aurora, and she saves his life by administering the antidote and unknowingly using a new ability through their bond to calm his feral wolf. Callum defeats James in combat and becomes King of the Northlands after James forfeits the throne and escapes. However, the forced kiss leaves Callum unable to move past his jealousy and uncertainty about Blake's connection to Aurora. At the same time, Kai, one of the rescued prisoners, briefly becomes possessed by a mysterious force connected to Night and delivers Alexander's warning that Aurora must be surrendered or war will follow.

Philip, Aurora's older brother and heir to the Southlands throne, unexpectedly arrives carrying a marriage proposal from Queen Ingrid of the Snowlands to unite the wolf kingdoms against Night's growing followers. Although Aurora had always believed Philip was an irresponsible drunk, he reveals that he secretly became a wolf after being bitten in the palace dungeons and trained as a warrior in the Snowlands. Which Aurora realized makes sense, since she is half wolf, it would make sense that any of her sibilings would be as well. 

Since being bonded to Blake, she has constantly been trying to find a way to break the bond. One evening, Blake lets her ask any question she has concerning it. This leads her to Blakes room, where Aurora later discovers Blake's journals describing horrific medical experiments on wolves, including procedures performed on himself while imprisoned beneath her father's palace. Blake confirms the journals are records of his torture rather than experiments he conducted, revealing that Aurora's father's Maester of Healing systematically abused wolf prisoners for years. Blake burns the final pages of the journal before Callum has him imprisoned, but Aurora investigates the missing word she glimpsed, "Anam-Cridech." The castle cook explains that it refers to the sacred mate bond created by the Moon Goddess, which cannot be broken and lasts beyond death. Aurora realizes the bond linking her and Blake is not an artificial connection he created but an eternal mating bond, but rather the real thing. Callum admits he discovered this truth after Blake kissed Aurora and deliberately hid it because accepting it meant losing her. Although Aurora and Callum finally consummate their relationship, they both acknowledge that wolves will never accept their union while the mate bond exists. Aurora decides to search for the Heart of the Moon so she can destroy the bond and remain with Callum. 

Callum sends Aurora north under Philip's protection, believing Madadh-allaidh is no longer safe for her. He also has taken Blake and put him in prison so he won’t go looking for Aurora. Though they both know that it will only last so long before he comes looking for her. During their journey, Philip explains that Alexander was the wolf who bit him years earlier, making Alexander his alpha. Alexander's forces ambush the group, forcing Philip to submit to his alpha before both he and Aurora are captured and taken to the Grey Keep. Aurora discovers James, Claire, and Ryan imprisoned there as well, all intended to face the monstrous Dark Beast hidden beneath the fortress. Alexander has Aurora chained in an ancient amphitheater and repeatedly whipped with silver in an attempt to force her hidden power to awaken, but the torture only causes her to relive childhood abuse she suffered in the Church of Light and Sun. Blake arrives with Jack and Arran to rescue her, publicly declaring Aurora as his mate before every wolf present. Alexander releases the Dark Beast, a massive shadow creature connected to Night, and Blake urges Aurora to stop suppressing the power she has carried her entire life. Aurora enters a vision where she speaks with her mother, who reveals that their bloodline descends directly from the Moon Goddess and the Elderwolf. She learns the Heart of the Moon is not an artifact but a title carried through the female descendants of their family; something that she now holds. Her mother knowingly sacrificed herself to protect that secret from Night's followers. Aurora embraces her inherited power and releases an overwhelming burst of moonlight that destroys the Dark Beast.

After witnessing Aurora destroy the creature, the assembled wolves kneel before her, and James acknowledges her as the true Heart of the Moon. Before the victory can be secured, Alexander cuts Blake's throat from behind. Arran immediately kills Alexander, but Blake begins dying and the mate bond starts to weaken. Aurora realizes she has the opportunity to sever the bond and free herself, but instead enters Blake's consciousness, finds him trapped in the memories of his childhood suffering, and rescues him, permanently strengthening their connection and saving his life. In the aftermath, Aurora enters another shared dream where she witnesses Blake's past. She learns Blake died during the torture beneath her father's palace and was resurrected by the imprisoned God of Night, who made him his champion and ordered him to find the Heart of the Moon so Night could escape his prison. When Blake wakes up, he confirms he made a bargin with the God of Night himself, and has been doing his bidding ever since. Blake never realized the Heart of the Moon would be Aurora herself and had genuinely fallen in love with her despite his original mission. As Night's forces prepare to invade, Blake reaches out to her, and Aurora chooses to take his hand.