Columba's Bones: Darkland Tales by David Greig

In a bloody, brutal raid, Abbot Blathmac is slain on the steps of his monastery for refusing to give away the location of the sacred relics of St Columba, the missionary who first brought Christianity to Scotland. Following a night of rampage and mayhem, one Viking wakes up the next morning to find himself alone, hungover, and abandoned by his crew mates. He can't swim, there are no boats, and the only surviving monk on the island has taken his sword. With only his wits, he must survive long enough not only to rejoin his Viking comrades, but also to find the location of the elusive relics that brought him here in the first place.

Rooted in the real history of Iona and its early monks, Columba's Bones is an utterly unique and thrilling book, exploring the clash of early Christianity and paganism, and expanding into a sharp, witty meditation on philosophy, redemption, shame, violence, love, transcendence, and reality.