A Scar in the Bone by Sophie Jordan

Here is a summary with spoilers for A Scar in the Bone by Sophie Jordan

In a prologue, a single human mother has been staying hidden and protecting her children—twins whom she doesn’t want the dragons to find. She loves them both, despite their personalities being very different. But eventually, the dragons find her, kill her, and take her children.

It has been a year since Tamsyn and Fell found out they were dragon shifters. A year since Tamsyn stopped being the whipping girl for the royal family and became Fell’s wife and eventually mate. However, a year has changed a lot, and Fell and Vetr (Fell’s long-lost brother) have been sent out on a mission, and only Vetr returns. Vetr tells Tamsyn that Fell is gone and that the bond she feels is just a lingering feeling and that she needs to move on. Even worse, after a few weeks of mourning her lost mate, Vetr comes to visit her and tells her that she has a new reality. She needs to be part of the dragon clan, protect them, and be one of them, because it will be her duty to find a new mate and become a dragon breeder so their kind can continue to grow. Tamsyn is devastated by this but slowly comes to terms with it.

With nowhere to go, Tamsyn decides to embrace her new role in the dragon clan. She continues to train, even though she gets beat up often, and she tries to make friends and really be part of the family. She integrates well enough that Vetr chooses her to come along for a mission—to go back to her old kingdom and gain some information. However, as soon as she gets into the city limits, it is clear that Stig, her old lover and current Captain of the Guard, has been looking for her. Everyone is on the search for a lookalike to the princess, and she is quickly taken captive. Stig arrives and tells her that because she is a dragon, she is going to slowly die. He gets a whip covered in dragon scales and whips her a handful of times. It is pure agony for Tamsyn, but her whipping stops when her old sister, Alyse, tries to stop it all and Stig accidentally whips her. Stig has to leave Tamsyn to take his wife to a healer, and he looks scared about the incident. Tamsyn is left tied to a tree, and she finds a way to escape, even though she is in an incredible amount of pain. While stumbling in the forest, Vetr finds her. He admits he saw her get taken, saw the whipping, and also didn’t help her escape—it was all a test to see if she would give up the dragon secrets. Tamsyn is furious that he did that to test her and demands to be taken back. She passes out and needs a couple of days to heal, and during that time Vetr doesn’t leave her side. Vetr then announces that he has feelings for Tamsyn and wants her to choose him as well, and he is willing to wait for her.

The dragons now start to trust Tamsyn more. She has also come to realize that this is her only option in life. So she decides to move past the feeling of Fell and his bond and goes to Vetr’s room with the intent of seducing him. While there, she starts looking around and stumbles upon Fell’s necklace. She freezes, knowing that something is off, then Vetr arrives. He admits that he took the necklace and that there is a good chance that Fell is alive but suffering a fate worse than death—being buried alive. Tamsyn is furious that Vetr didn’t tell the truth, so she leaves but asks for time to think. Her thinking leads her to leave the dragon den and go on a search for her mate, Fell.

As Tamsyn gets closer to where she thinks Fell is buried, she runs into a witch who is also trying to escape from her people. She reveals that she knows where Fell is buried and offers to take Tamsyn there. A day later, they arrive, and Tamsyn starts searching for Fell, feeling him closer and closer. When she finds him, he shifts into his dragon form and kills everyone around him except for Tamsyn, though he does injure her. After fighting and Fell trying to come back to himself, Fell finally realizes who Tamsyn is. The two officially reunite, share an intimate moment together, and then decide they need to catch up on everything that has happened over the past year.

After Tamsyn shares what has happened over the past year, Fell is furious at his brother. Together they decide to go back to Fell’s position (Lord of the Borderland), which is Stig’s current position. They figure if they go back and Fell announces that Tamsyn is not a dragon (as the people have yet to see proof), then Stig will look like a fool. They start their journey back to their home and away from the dragon clan.

Very quickly, the two are separated, and Stig finds Tamsyn. Determined not to let her get away and to prove she is a dragon, Stig forces Tamsyn into a cage. She uses all her might not to show her dragon, and that is when Fell arrives and demands she get out. The people are thrilled that their leader is alive and well, but Stig is upset because, in his eyes, Fell is lying about Tamsyn’s ability, which is considered treason. Stig then starts to attack Tamsyn, but Fell takes the attack instead, and his blood spills, revealing it’s dragon-purple blood. The soldiers see, and Fell decides to unleash a massacre. He kills Stig and all the soldiers but leaves his people free. Vetr and some of the other dragons arrive as well, and Fell tells him that he and Tamsyn do not want any part of their clan, that they will stay in their lands and keep the dragon secrets. Vetr tells Tamsyn she is a traitor, and the dragons fly back to their lands.

Fast forward a year: the two are happy, even with the Krags (spelling uncertain, possibly from the audiobook) close by. Meanwhile, a king is preparing to take vengeance for his dead son by going to the Borderlands. To help him with his task, a witch is there, and she casts her curse.