"The First World War did them both in." That's the verdict Doris Lessing hands down in "Alfred and Emily," her stirring exploration of what life would have been like for her parents had history not stamped its indelible ink on their souls.

Lessing, a Nobel laureate and author of such acclaimed books as "The Golden Notebook," was born in Persia (now Iran) of English parents. Her father, Alfred Tayler, had been badly wounded in the trenches and wore a wooden leg the rest of his life. He suffered from diabetes and what Lessing now surmises was a crippling depression. "You put a sick old dog out of its misery, why not me?" he begged. His wife Emily's great love was a doctor who drowned in the English Channel. She spent the war nursing the wounded in London's Royal Free Hospital.

Despite these tragedies, the marriage got off to a promising start when Alfred took a job as a clerk at the Imperial Bank of Persia, mostly because the expatriate social whirl suited Emily. When Doris was 6, the family bought a small farm in the British colony of Southern Rhodesia (now Zimbabwe). But when it turned out to be an unproductive swatch of the African bush, Emily took to her bed for months. Eventually, Lessing writes, "She got up, and what that must have cost her I cannot begin to imagine. She was saying goodbye to everything she must have expected for her life in this colony." Her evening gowns were chewed by moths and eventually cut up into costumes for Doris and her dog.

Among the Liberty print fabrics, BBC radio programs and other talismans of British life were the bundles of English and American books Emily ordered from London. Lessing gobbled up the classics, including "The Secret Garden," "Anne of Green Gables" and "Pollyanna." But while their parents' deaths freed those orphaned girls to take center stage, Lessing uses the first half of the book to turn the idea upside-down. "Alfred and Emily" begins as a novella in which she imagines their lives had the war never happened. The fictional Alfred and Emily never become more than friends; Lessing writes herself out of her own life.

That's a curious liberation, but necessary; Lessing uses these invented scenarios, which she based on facts and less tangible clues such as "tones of voice, sighs, wistful looks, signs as slight as those used by skillful trackers," to understand her parents and the impact they and the war had on her. It's that intimate agenda and Lessing's refusal to drift into nostalgia that make Alfred and Emily's could-have-been lives gently yet deeply moving. In fact, you become so attached to Alfred and Emily that it is almost impossible to not want Lessing to make these cheerier scenarios more, well, cheery.

She's too keen an observer of human nature to go that route. Instead, she brings us two people who are just on the other side of melancholy. Ambitions aren't achieved; people use each other; epiphanies about love arrive too late. Lessing knows that contemporary readers have come to expect that even their Kodak moments are digitally enhanced. With her toned-down version of happiness, she seems to be saying that true contentment rests in the ordinary moments after the flash pops and the grins fade.

The second half dissects Alfred and Emily's marriage as it actually was. More like a folder of supporting documents, this memory archive is at once tender and unsparing. Lessing admits that she hated her mother, which won't surprise anyone who has read "Martha Quest." But she has genuine compassion for her parents' suffering and the role that history played in shaping it. She circles back again and again to the "clever medicine we have now." Surely, advances in the way we treat diabetes would have lessened her father's agony. And had antidepressants been available -- or had her parents just lived in a culture fluent in pop psychology -- she believes they would probably have gotten through the dark times more easily.

Unfortunately, Alfred and Emily didn't live in a time where people can readily parse the differences between Paxil and Zoloft. Their daughter is now 88. Rumor has it that "Alfred and Emily" is her last book. If that's the case, it's fitting that Lessing has refused to tie up the latest reckoning of her life with a storybook ending.

Elizabeth Larsen is a Minneapolis-based freelance writer.