To Charm a Dark Prince by Kathryn Ann Kingsley

To save a kingdom, she must charm a monster.

Transported to the magical realm of Avalon, Gwen finds herself in the hands of its dark and beautiful ruler—Mordred, the Prince in Iron.
The prince holds total power in Avalon, trapping his rivals in an enchanted crystal prison. But he shows a strange gentleness to Gwen.
Seeing no other way to escape, Gwen strikes a deal with Mordred’s enemy. If she can break the crystal, she will be free to go home.
Gwen joins Mordred’s court with a plan to steal his heart and destroy his prize.
Desire sparks between them at once. But Mordred is a dangerous host. As they draw closer, his passion and anger burn brighter.
Gwen would be foolish to trust him.
And even more foolish to betray his trust…