Lyla is a Sirius princess married off to Damon, head of the Black Dragon clan, for politics. Two years pass and he barely appears, then he brings home Serina, the woman who once saved him, and starts arranging a second marriage. Lyla isn't angry about it; she wants the blood oath contract dissolved so she can take her assets and leave, and Damon won't release her because he needs the alliance.
An accident drops her into a secret ritual performed by Kyle, Damon's uncle and the Dragon Emperor, and the two are bound in a soul oath that shares their lives and forces a monthly exchange of blood. Serina keeps taking pieces of Lyla's position while Damon looks away, and when Lyla goes home to her own clan, her stepmother frames her. Kyle is the only door left.
