An ancient pact. A rising darkness. A search for truth.

For five thousand years, the bargain held.

Until the winter solstice fifteen years ago, when Lydia Blake lost her family and city at the hands of the gargoyles, humanity's sworn protectors.

Now all she knows is vengeance, with the stain of her enemies' blood on her hands and her soul. One name remains on her list: the man who she believes murdered her family.

When his life is finally within her grasp, he presents the possibility that everything she remembers about Solstice may be a lie.

As Lydia attempts to find the truth, an ancient enemy of both man and gargoyle stirs for the first time in fifteen years—striking with precision and an intelligence they shouldn't possess. The longer Lydia spends with the gargoyles, the more she begins to suspect Solstice is at the center of it all.

As her memories of that night begin to shift, Lydia must decide if she is hunting the monster, or becoming one.