Burnt Shadows, by Kamila Shamsie

Just three days after the Little Boy atomic bomb detonated over Hiroshima, the Americans readied to drop the second bomb over Kokura. Cloud cover diverted the B-29 to Nagasaki instead. Historians have argued over the efficacy of those decisions to end the war: Was it really the only way to avoid an estimated one million American deaths? Revisionists now counter that it was the Soviet declaration of war an hour before the bombing of Nagasaki that had the greater impact. For novelist Kamila Shamsie, another question is more significant: What makes a country think that one Hiroshima is not enough?

This is the quandary that pulses throughout Burnt Shadows, the fifth novel by the Pakistani-born writer and her first published in Canada, its reverberations echoing through the intergenerational story of two families, the continually displaced Weiss-Burtons and the Tanaka-Ashrafs, caught up in the tumult of history from the "New Bomb" to 9/11.

• Burnt Shadows, by Kamila Shamsie, Bond Street, 370 pages, $29.95

Like other Pakistani writers, such as Nadeem Aslam and Mohsin Hamid, she is preoccupied by that ungainly ménage à trois that is Afghan-U.S.-Pakistani relations. Add in the nuclear tensions between India and Pakistan, and Shamsie, who comes from an illustrious writing family, has the scaffolding for an ambitious, beautifully written and mostly successful novel.

Shamsie is a masterful storyteller, beginning the novel with a mysterious episode in which an unnamed man, naked in a cell, awaiting his future, wonders, "How did it come to this"; then whisking back in time to the hours before the blinding white light of the bomb seared Nagasaki. There we meet schoolteacher-turned-munitions worker Hiroko Tanaka, daughter of a "traitor," as she becomes engaged to Konrad Weiss, a German who, arriving before the start of the war, found refuge in Japan.

The bomb changes everything for Hiroko, who loses her fiancé and her father, but gains three cranes etched into her back, tattoos from the kimono she wore at the time of the blast. She is a survivor, a hibakusha, rootless. Her talent with languages has her translating for the victors in Tokyo, careful to distinguish a people from the act. When she finally hears an American explain the rationale behind the bomb, she leaves Japan for New Delhi, the home of Konrad's half-sister. While Hiroko catches only glimpses of her fiancé in Elizabeth Burton (née Ilse Weiss), she begins to find peace in her friendship with Sajjad Ashraf, a young man discovered by Konrad and introduced into the Burton household, as he teaches her Urdu.

Shamsie constantly shifts the point of view so that no one character has a monopoly on empathy or confusion. Everyone, even the next generation, has to grapple with their strange outlier status, their peripatetic ways resulting in the remaking of selves.

Hiroko sees the coming violence of the partitioning of India, "a swerve in history," and persuades Sajjad to leave his beloved Dilli for her, only to find he cannot return.

Shamsie has a poet's touch to her writing. Her description of Hiroko and Sajjad's first lovemaking is delightfully playful. For the most part, she handles her material well, even in the final third of the novel, when she piles on a litany of issues set in the months after Sept. 11, 2001.

It's a shame, however, when Shamsie flattens her novel by using lists as a way to set a scene; or worse, by having Harry and Raza, now colleagues for a defence contractor and sharing an apartment in New York with their mothers, seemingly provide the cheat sheet for Book Clubs everywhere. Want to know all the ways the two families have affected each other? Page 356 has the answer!

It is Henry's daughter Kim who moves the novel to its final climax, struck numb by 9/11 and worried over her father's "work" in Afghanistan. She alternates between the Ugly American and her devotion to Ilse and Hiroko. While Shamsie mistakenly has Kim declare that structural engineers, like herself, knew the towers would fall before it happened, the reason is obvious: to show how Kim relies on her certainty at moments of crisis. So when it is her turn to be tested, it is that attitude that guides and eventually fails her, especially in the eyes of Hiroko. Burnt Shadows is a haunting novel about love, loyalty and sacrifice in a world forever "blown off-course."

Piali Roy is a writer and broadcaster in Toronto. Her two-part documentary, The Bhagavad Gita, aired on CBC Radio's Ideas.