Shadows and Twilight (The Dragon Portal, #4)

The only way for darkness to thrive is to destroy the light... Sabine owes her life to the two demon brothers who helped keep her hidden from the fae for the past ten years. ​ When she learns Dax has been forced back to the underworld to stand trial for his treasonous crimes, Sabine races to their volcanic home to save him. What she discovers is a long-hidden truth that has the potential to shape the future of their world or destroy it. Only an ancient weapon of power can shatter the portal's bindings... The demons secretly recognize Sabine as the true queen of the Unseelie, and they're determined to keep her for their own purposes. With her magic, they can escape the underworld and declare vengeance on those who oppose them. ​ But first, they must destroy all her ties to the light, including the man she loves.