Night Demon. Night, #2

Lisa Kessler is an up and coming author to remember - Sherrilyn Kenyon - #1 NYT Best Selling Author of the Dark Hunter SeriesGretchen Finch's job would be much easier if she weren't alone in the jungle with a brilliant recluse whose every glance sets her on fire. But the more she focuses on her work, the closer she gets to unlocking the mysteries of a terrible creature--the Night Demon--that threatens the world as she knows it.
Though her scientific mind tells her it's impossible, she's beginning to believe the ancient Mayan tales as the sinister jungle comes alive around her. Lukas Smith has spent hundreds of years searching for answers to his immortal Night Walker nature. As a series of ancient glyphs become clear, he's about to find out more than he'd ever hoped, but the more he learns, the more his fate intertwines with the Night Demon, and the harder it becomes to hide his immortal secret from the beautiful, intelligent Gretchen.
Gretchen holds the key to saving Lukas, the Night Walkers, and mankind from the Night Demon's violence surging across the earth. But his feelings for her cloud his judgement, and if he's forced to choose between Gretchen and the world, he might let it all burn...