Hot on the trail of the mysterious enemy they know only as "the dark rider," the Blue Triad find themselves, not in any of the known territory of Tir na n'Og, but lost in the Mists; a place of innumerable dangers and subtle horror. While battling their way through hordes of monsters straight out of nightmares, the three heroes uncover a terrible, long-lost secret—and an even more terrible threat—brewing in the shadows. Only Yaqut ibn Munquidh's legendary sword skills, Antonio DeVasa's magic, and Angharad's ferocious cunning keep them one step ahead of the evil they awaken.

But will they be able to carry their warning to the Fey, and all of Tir na n'Og before another of the dark rider's allies unleashes an ancient menace that threatens not only the land they are sworn to protect, but the very bond that unites them?