In both her contemporary and historical fiction, Emma Donoghue is fascinated by madmen, fanatics and extreme, confined situations, with "Room," of course, being the best known of her many books. In her latest, "Haven," she transports these concerns to seventh-century Ireland, imagining three monks struggling to survive on a rocky island inhabited previously only by tens of thousands of birds.

According to an afterword, the island is real — it's called Skellig Michael, and it was used as a location in "Star Wars" movies — and Donoghue's story has its roots in a historical tradition of Irish monks retreating to remote places to claim them for God.

The leader of the trio is a man called Artt, a wandering scholar and priest who shows up at Cluain Mhic Nois, a monastery on the River Shannon. He has "the bearing of a warrior king but he behaves like a scrupulous monk working out a long penance."

To the youngest monk, Trian, Artt is the most interesting person he's seen in the six years since he was given to the abbot by his parents at age 13 — for reasons which are withheld until the dramatic final chapters. So when Artt has a dream that he must take two monks with him on a journey to an uninhabited place, Trian is pleased to hear that one of them is him.

The other is Cormac, one of the oldest monks, a garrulous storyteller who found his religious calling late in life after losing his wife and daughters to the plague. Artt has chosen well, since each of these men has skills that will prove essential, and they take vows of obedience which put these skills at his disposal.

The bad news is that Artt is a jerk, to put it bluntly, continually overruling reasonable proposals made by his two disciples in favor of holy activities. So instead of building a shelter, Cormac must build an altar and a chapel.

Poor Trian, who is a talented fisherman and lover of nature with no skill at all for reading or copying, is put to work doing just that from dawn to dusk. Most appalling, instead of traveling to the mainland to trade, they must make do with what they can find on the inhospitable skellig, even as they deplete what little resources it offers. Slowly Trian and Cormac come to fully understand what the awful Artt has in mind for them.

Donoghue's characterizations of the three men, her vivid imagining of the measures they must take to survive, and her beautiful descriptions of the landscape and wildlife — puffins galore — make this book readable even for those who don't care much about medieval Christianity.

A strange turn of events having to do with Trian's secret brings the book to its climax. Donoghue is good at endings, as readers of "Room" know, and here again she metes out narrative justice with a firm hand.

Marion Winik is a writer, professor and book critic in Baltimore.

By: Emma Donoghue.
Publisher: Little, Brown, 272 pages, $28.