Kiss of Darkness - The Dragonfire Novels, #11

Damien, the Heartbreaker of the dragon warriors called the Pyr, can't forget Petra, the only woman who could both captivate him and destroy him. He's haunted by their firestorm, the prophecy that compelled him to leave her-and her subsequent death. When the darkfire crystal takes the Dragon Legion to the underworld, Damien seizes the chance to save his son. To his surprise he finds Petra just as enticing as ever.and still pregnant.
When his kiss makes their baby stir to life again, they both hope for a different future. Can they learn from the past and trust each other? Even if they solve the riddle of the prophecy, will they be able to escape the underworld, save their son and claim the promise of the firestorm?