Though Heartless can be read as a stand-alone, begin the series with Breathless in order to learn the full impact of Nighthawk’s incarnations.

Karma never felt so good, but there’s a dangerous price to be paid for succumbing to temptation.

Amid the volatile backdrop of WWII, Raoul Fortier, an on-the-run French Resistance fighter escapee, has just been possessed by Nighthawk’s spirit when he encounters armed, hot and handsome Kilian Rheinfeld in the Jura Mountains near the Swiss border. Lust and love bloom between the two men who realize they were lovers in another lifetime. But there’s more to Kilian than meets the eye, and for Nighthawk, peril lurks ahead yet again in the form of bittersweet karma.