As deadly as she is beautiful, Zahirah, daughter of the King of the Assassins, steals into the camp of the English army. She intends to murder King Richard, but her plan only delivers her into the hands of the enemy and puts her at the mercy of the dashing Black Lion, Sebastian of Montborne. Seeing only a mysterious beauty in need of his protection, Sebastian is unaware that Zahirah is the enemy he has sworn to destroy. Caught in a web of passion and deception, they now risk their lives to share a forbidden love.