A year or so back, a friend gave me a copy of a beautifully crafted memoir entitled “Of Flesh and Blood: A History of My Family in Seven Sicknesses.” It is written by Dr. Turner, from “Call the Midwife,” or more accurately, it was written by Stephen McGann, the actor who portrays Dr. Turner. He has chosen a fresh and clever architecture for this book. He uses illness as the load-bearing walls to support the textures and patterns, the shape of his family over time.

Like all good memoirists, he begins with a question. How did the McGanns go from a family of extreme poverty in Ireland to a flock of successful and siblings, actors whose names glittered on marquees, the brothers sharing real estate on theatrical posters, grinning out at us with those larger-than-life and  handsome faces?

How did this occur in a relatively short time, a span of a 150 years or so, especially when so many of the McGanns “failed to thrive” in infancy, died of starvation, in fact, during the potato famine? How was it his branch of the McGanns found their way to Liverpool, still poor, still vulnerable to diseases from overcrowding and poverty, but with hope for a different outcome?

McGann sets out to answer these questions, delving into family birth, marriage and death records, researching illnesses and sussing out secrets, until he comes to the page like a builder might, unfurling his technical drawings, tracing with a finger the medical and historical context of one illness after another, this backward-looking blueprint of how he has come to be, and from whom, and why.

The result is a sophisticated piece of writing, elegant in its use of language, but the real strength of the book lies in the rich and engaging way he tells us about his people. McGann’s work is clear-headed and clear-eyed, honest, deeply personal but never sentimental. You can trust this one, you think, and you are happy to sit with him and hear his stories for as long as he wants to tell them.

As fascinating as “Flesh and Blood” is as a memoir, I was equally fascinated by this.

Stephen McGann became interested in genealogy and he began collecting and researching his family history at a young age—as an adolescent, a high school student—a kid.

I think of genealogy as the great endeavor of the geriatric, the retiree, at the very least the middle-aged.

I am gratified and oddly reassured by his youthful enthusiasm, and I like to imagine him, this young lad with his hair flopping in his eyes, bending over dusty family Bibles, and dustier family records and photos in boxes in attics or basements. Perhaps he shared table space with an octogenarian in a courthouse records room somewhere, as they asked each other, Can you read this—“Is it a T or F?” or “ What is that date? Does that look like a 3 to you?”

In the past week I have talked to my cousin as we have worked to make sense of some new information she has uncovered. She, herself, is recently retired, and a genealogist, and right now she is working on our side of the family.

She can list the names and birth order of my grandmother and her siblings. I can never remember if there were six children or seven. They were born in Indian Territory, 120, 130 years ago.

Granny told us stories of her childhood when we were young. I loved the stories, of course, but when I was the perfect age to start paying real attention—in adolescence, in my twenties—I couldn’t be bothered to ask questions, to write things down.

And now there is no one to ask.

And there is a family mystery.

But there is also a new cousin out there, one we didn’t know about, a granddaughter of one of my grandmother’s sisters, living in Illinois, I think.

With this mystery and this new relative, I am beginning to see the appeal of all this family history business. That genealogy isn’t just a remedy for boredom, like working jigsaw puzzles, something easily done sitting down. There is the hunt, the discovery. There is the unexplainable something —call it resonance, connection—that comes with knowing your people. Knowing their stories. Making sense of those stories, making sense of yourself.

Stephen McGann’s book, “Of Flesh and Blood” sneaked up on me, helped me think of family genealogy in a new way. That the search for family history begins as all good mysteries, as all good memoirs do, with a question, and then another one, and another.