From the dreaming spires of Oxford, graduate student Lewis Gillies and his impulsive roommate, Simon, drive north to seek a mythical creature in a misty glen in Scotland. Once there, Simon vanishes through a hole in the cairn, and Lewis follows him to a mystical place where two worlds meet, in the time-between-times. There, where Celtic champions, magic, and treachery weave the beautiful and brutal land called Albion, Lewis finds Simon. And there, schooled as a warrior, he is thrust to the front of a titanic struggle between light and darkness—a hideous, onrushing darkness that would devour not merely a kingdom but two worlds. The ancient Celts admitted no separation between this world and the Otherworld: the two were delicately interwoven, each dependent on the other. The Paradise War crosses the thin places between this world and that, as Lewis Gillies comes face-to-face with an ancient mystery—and a cosmic catastrophe in the making.