How well – no, make that how unwell – do we know our parents? Ten years ago, when my grandmother died, after the estate had been lawyered at and tidied away, a bequest of her papers fluttered down on my parents. I remember sifting the pile: there were deeds and menus from official dinners, old Edmonton Journal clippings, recipes, my grandmother’s lost poems.

And a teeming file of pages covered in faded blue ink, every last letter and card my dad had written to his parents since leaving home 30 years before. I sat there and read through them, amused at first, then steadily more and more astonished – not only by the force of thriving life but by how much was new to me. Months later, as I was reading an Ian McEwan novel, The Child in Time, a line jumped off the page at me. “It is difficult to step outside the moment on any given day and ask the unnecessary, essential question, or to realize that however familiar, parents are also strangers to their children.”

The Winnipeg novelist Miriam Toews began to understand how much of a stranger her father was when she lost him. Lost – that’s one of those weaseling words we like to use when someone’s life ends, as if making death sound like carelessness could somehow allay the raw pain felt by those who’ve survived. In this case, though, it’s the right word, because Toews lost her father first, before he killed himself.

In the early 1950s, when he was 17, Mel Toews of Steinbach, Manitoba, was diagnosed as suffering from the mental illness then known as manic depression (these days it’s bipolar disorder). It didn’t look good, his psychiatrist told him, he probably shouldn’t count on marrying, starting a family, holding down a job. Mel went ahead with all three: married a pretty nurse by the name of Elvira, helped raise two daughters, was a passionate and beloved schoolteacher for 40 years. For all that time he was able to keep his depression in check. But then he retired.

Toews, whose 1998 novel A Boy of Good Breeding was sweet and funny and undercelebrated, tells us all this in her prologue to Swing Low. She tells of the two words he whispered to her the day before he died: “Nothing accomplished.” He was in the hospital then, sad and confused and silent. Now and then he’d asked his daughter to write things down for him, in the first person, to help him understand when he read the notes back to himself. When Miriam decided, after his death, to write about her father, it just seemed natural to go on using his voice.

For what? Well, for one thing, Miriam writes, she was intent on erasing that bleak phrase of her father’s, wanted to prove to herself, at least, just how much Mel did accomplish in his life.

All of which is to say – in case you hadn’t quite worked it out – that Swing Low is an acutely personal document. It doesn’t matter that it’s as much a work of imagination as any novel – coming out of the prologue, the simple act of turning the pages feels like a rudeness, an intrusion. And yet of course the intrusion is invited: by publishing this book, Toews is offering it as a public, literary artifact. On that count – as a story – this is a fine, fluent book teeming with anecdote and incident, echoes and images.

It can’t be easy to write a chronicle of a death foretold, to say to your reader at the start, here’s how this book ends, but don’t worry, I’m still going to surprise you along the way. Toews pulls it off in bravura fashion.

She even puts Mel in a hospital bed at the outset. He’s had some kind of decisive breakdown, or maybe it’s just that looking after him and his depression got to be too much for Elvira. Anyway: he’s here in the hospital, and he’s writing. There are murky times, where things start to get confused. Did he maybe murder his wife and forget? How did his feet get so blistered? The nurses talk to him as they might a two-year-old. “I understand I baffle them,” he writes. “I baffle myself.”

He’s lucid enough to wonder how he got here, what’s wrong with him, whether there’s a way out. “I’m a methodical man so this business re: losing my mind is frustrating,” he writes. And: “Perhaps depression is caused by asking oneself too many unanswerable questions.”

By the time it dawns on methodical Mel that the writing is helping, that he’s reclaiming his life, finding “a place of understanding” amid all the confusion, he’s already well on his way to recounting the story of his survival. It’s a detailed, textured portrait, not just of a human life, but of a community, of small-town, Mennonite Manitoba.

Miriam leaves Mel on the last day of his life, a few hours before his death. In an epilogue, in her own voice, she sketches out the final act of his life. We don’t know whether, in real life, Mel reached his place of understanding. In any event, he found a way to end his pain. Miriam Toews still has hers, but after Swing Low, she writes, it’s less than it was.