Set in the early years of the 14th century, "Crossroads" is the third volume of Norwegian Nobel laureate Sigrid Undset's tetralogy, "Olav Audunssøn." Given that it's one part of a whole, you'll be lost unless you've read the previous two volumes; even to describe this book involves spoilers — if such can be said about a work published nearly a century ago and translated into English shortly after (as "The Master of Hestviken").

Be that as it may, the new translation, beautifully rendered by Tiina Nunnally with her customary briskness and clarity, is the version to read, though you will have to wait until next year for the conclusion.

The previous installment, "Providence," ended with the death of Olav Audunssøn's wife, Ingunn, the love and torment of his life. Olav's and Ingunn's irregular betrothal flouted the wishes of her near relations, out of which came the couple's subsequent tribulations, among them two murders, exile, rape, an unwanted child and a betrayal of blood ties. Olav's soul became a morass of love, hatred, shame, guilt and resentment — and pity for Ingunn who, never especially stoic, had become a querulous invalid. In the end, she gave birth to a daughter, Cecilia, and died when the child was but a toddler. Olav was heartbroken — and relieved.

So here we are: Olav is "suffocating in the dark room of the long night of mortal sin," burdened by a dire unconfessed crime and an offense against Norse blood ties. His life is a tangled mess, impossible to set straight without losing everything, including his honor. He shares his home with Cecilia and Eirik, Ingunn's son whom he had claimed as his own to protect his wife's character.

But Olav is not a kind man and constantly rebuffs the boy in his attempts to win the love and respect of the man he considers his father. As a result, Eirik has become a terrible braggart and fantasist. Olav feels moments of compassion toward the needy, adolescent boy, but the feeling soon dissolves into his own self-absorption, corrosive guilt and resentment. Put bluntly, Olav is a real pill.

Although the book is filled with incidents including a trip to England, much of it is played out in this wretched man's inner world and Undset's psychological acuity here and in her portrayal of Eirik's troubled soul is extraordinary and wrenching.

Their emotions and impulses arise naturally out of the personalities she has so perfectly conjured. She is also a master of evoking a vanished way of life and, above all, of nature's vitality, of weather, of land- and seascapes, exhilarating images that freshen a story that is deeply tinctured with anguish and uncertainty. Happily, Olav's spirit is not terminally sunk in Nordic gloom. He becomes alive at last, his Norse blood truly roused, when Swedish troops invade Norway and we are treated to fast-paced, early-14th-century battle action. And so we leave our problematic hero until next year and the finale.

A Minnesota native, Katherine A. Powers also reviews for the Washington Post and the Wall Street Journal.

Olav Audunssøn: Crossroads

By: Sigrid Undset, translated from the Norwegian by Tiina Nunnally.

Publisher: University of Minnesota Press, 256 pages, $17.95.