In "I Refuse," Norwegian author Per Petterson turns his immense talent to exploring the power of friendship, the passing of time and the lasting effect of small actions.

The story of childhood companions whose adult lives have diverged will feel familiar to those who have read Petterson's other works, including "Out Stealing Horses," which won the International IMPAC Dublin Literary Award in 2007. The steely northern landscape, the absent parents, the excessive drinking — all are summoned with the precise language of a poet, and translated by Don Bartlett. Yet while Petterson's other novels settle in your heart gently, this one winds up a rocket. "I Refuse" is the author's most emotionally layered and powerful novel yet.

The tale begins when former best friends Jim and Tommy encounter each other on a bridge. Jim is fishing when Tommy happens by during his commute. The two haven't seen each other in 30 years, and it is not an accident that the meeting occurs in the obscure light of dawn. As boys, they relied on each other, knew each other "through and through." Now, they fail to connect, in the first of several missed opportunities that wend through the anguished tale.

The most pivotal occurs when the two, at 18, go ice skating on a frozen lake lit by the moon. A chance occurrence there comes to haunt their relationship.

No one would have predicted Tommy's wealth. His mother left him and his three sisters to fend for themselves with an abusive father. When 13-year-old Tommy finally retaliates, armed with a baseball bat, the father also vanishes, and authorities separate the children. Tommy moves in with a taciturn but loving neighbor, Jonsen. In adulthood, although Tommy is a successful trader, he drinks too much in an attempt to mask his loneliness.

Jim is Tommy's rock through the turmoil, a thoughtful boy raised by a Christian mother. He does well in school, but falls into a depression and attempts suicide. The last place Jim and Tommy meet as youths is the hospital where Jim is receiving treatment. When he is released, he and his mother move to Oslo, away from the neighborhood where Tommy remains. Grown Jim has fallen into depression again, rudderless after briefly holding a top job at the Oslo libraries.

The story is told in chapters that skip years and narrators. Short sentences are followed by sentences many lines long; they never confuse, but instead reveal the interior life of the narrator. Here is a telling example in Tommy's voice: "The crooked pine was the tallest and was split from the top right down to the middle and from there it grew up again like two completely different trees and the one didn't know what the other was doing."

Other characters get cameos; chapters devoted to Tommy's mother are particularly moving. As the story progresses, tension builds. I found it gripping because I cared deeply for the characters. For that same reason, reading was difficult. But that should not stop people from immersing themselves in this masterful work.

Kerri Westenberg is the Star Tribune's travel ­editor.