When Nuruddin Farah writes fiction about the ravages of terrorism, the details may be imaginary but the scars are real. The celebrated Somali novelist, a frequent contender for the Nobel Prize in literature, lost his sister Basra Farah Hassan in 2014. A nutritionist working for UNICEF, she was murdered, along with at least 20 others, when the Taliban bombed a restaurant in Kabul.

Farah’s new book, “North of Dawn,” places its characters far from flying shrapnel but deep in conflicted grief. Like his previous novel, “Hiding in Plain Sight,” it’s concerned with difficult questions of forgiveness and recovery in the aftermath of violence. The story opens in Oslo, when a Somali diplomat named Mugdi gets word that his only son has blown himself up at the airport in Mogadishu. Mugdi and his wife, Gacalo, suspected their son was radicalized; the news of his death makes it impossible to ignore the truth.

Shocked and disgusted, Mugdi wants nothing to do with the memory of his late son. “How can I mourn a son who caused the death of so many innocent people?” he asks. “I explode into rage every time I remember what he did.” But his wife refuses to relinquish her love for the young man, and she’s determined to keep their parental connection alive by inviting their son’s widow and her two children to Oslo. That invitation, sent on the wings of affection and duty, ensnares Gacalo and Mugdi in a complicated kindness that will alter the rest of their lives.

“North of Dawn” is a rare tale concerning the terrorist’s family that takes place in the long shadow of grief, shame and twisted loyalty. It’s also pulsing with a toxic mix of zealotry and xenophobia.

It’s not hard to imagine that Farah, who currently lives in South Africa, has infused the protagonist with his own dismay. Mugdi is a Somali who “detests Somalia’s dysfunction.” He’s a foreign-born resident who fears his host country’s growing intolerance. He’s a spiritual man who has lost his faith in organized religion, though “the ringing of the muezzin stirs memories within him.”

As the novel opens, Mugdi is thrust into the awkward role of welcoming a daughter-in-law poisoned by the same radicalism that turned his son into a killer. She arrives from a refugee camp in a state of terrified bewilderment, fully cloaked, unwilling to speak to him — or any man — directly.

“North of Dawn” is bracingly honest about the difficulties of assimilation, the way hospitality curdles into condescension and gratitude sours into resentment. Mugdi and his wife are extraordinarily generous toward their daughter-in-law, a young woman named Waliya, but Mugdi expects her to reciprocate by going to language classes, finding a job and becoming a productive member of Western society. Waliya, for her part, remains unwilling to do anything that might contaminate her. Alarmed by the permissive culture of Norway, she’s intensely alienated from her new home and determined to cling to her conservative practice of Islam ever more fiercely.

But for Farah, Muslim radicalism is not a problem in isolation. It’s merely one side of the coin of intolerance that’s gaining currency in liberal democracies. “We are caught,” a friend tells Mugdi, “between a small group of Nazi-inspired vigilantes and a small group of radical jihadis claiming to belong to a purer strain of Islam.”

“North of Dawn” suffers from a ramshackle quality one might expect from an exciting but not quite finished draft. There are strange gaps in the plot, and the prose sometimes slips into antique cliches.

More irritating, these characters often feel compelled to look out directly at the reader. With preternatural eloquence, Mugdi’s teen grandson declaims: “Somalis pay lip service to the faith while we live a life of lies. This is why the dissonance in our hearts continues to flourish, why there is no letup in the usual struggles within our minds, why the strife in our land rages on unabated.”

Farah would do better to place such an observation in an essay instead of cramming it in the mouth of a teen boy. The story he shows us through these characters’ derailed lives is more illuminating than anything they can explain to us.