If your home catches fire, you rescue your loved ones, then your pets. If you have time, you’ll grab your family photos. They are irreplaceable.

But if the bloodline ends, and the estate goes up for sale, they become something else: the photos of strangers. Usually they’re tossed in the trash.

The 60-year-old photo album of Janet Lee Dahl could have ended up that way. Thanks to her mother’s impulse to document the everyday details of her daughter’s life, it did not. Instead, a succession of people who ended up with the photos have felt a deep connection to Janet Lee through those haunting images. I am the latest one.

It started with a gift. In January, my daughter gave me a book called “Talking Pictures.” Compiled by Ransom Riggs, it features rediscovered vintage photos with writing on the back. My daughter and I are fans of Riggs’ better-known novel, “Miss Peregrine’s Home for Peculiar Children,” in which he uses found photos to illustrate a story about children with magical powers fighting against evil. A New York Times bestseller in 2011, the book spawned sequels and a Hollywood movie.

Published in 2012, “Talking Pictures” hasn’t found the same audience. This book is made up of single photos that tell fragments of stories. They tease the imagination, and force you to fill in the rest.

One chapter in “Talking Pictures” is all from the same album. It’s titled “Janet Lee.” The first image is of a girl standing with her back to the photographer, looking out at a large harbor dotted with sailboats. What follows are 16 photos of the girl, with annotations in clear block letters. Janet is riding on a “real pony,” and playing in the snow with a neighbor boy named Mark.

It quickly becomes clear that something is wrong. In one photo, the girl is smiling while sitting up in bed. “Janet Lee in hospital just before going for her (X-rays) test,” is written on the back. In another she’s posing with an older man. “Harold worries a lot about Janet.” A few photos later she’s on a couch lying with her head on Harold’s lap. “Janet had a little spell at Pointek’s cabin while she sat on the davenport. So I snapped them after it was over.”

Then she’s smiling, chin in hand, but you see her eyes and nose are puffy. “Janet Lee after last fall on bedroom floor — looked so pathetic with swollen bridge between her eyes. 7 x-rays on May 30th at Abbott Hospital — told no broken bones. Should buy a helmet for her.” Two photos later, she’s visiting Texas: “The last time she will ever be there for she died Aug. 18, 1959, in Abbott Hosp.”

In the photo that follows, Janet Lee lies in an open coffin. Her Raggedy Ann doll is propped next to her, poking out of the casket. The back of the photo is presented on the opposite page. It’s blank.

Riggs wrestled with whether to include that photo in his book. He felt compelled to show the back, because it expressed the “void of unspeakable pain.”

The pictures of Janet Lee provoke so many emotions — and so many questions. Why would someone take these pictures? How did they end up in this book?

Something else stood out to me. Three of the captions mentioned Abbott Hospital. There was no identifying information, other than her name was Janet Lee and she died at age 10 in 1959. The possible Minnesota connection in a story of such a terrible loss triggered my investigative reflex. I had to find out everything I could about her.

In the weeks that followed, I learned far more about Janet Lee than I thought was possible. Her story endures in handwritten notes on the backs of printed photographs, as intimate as a diary and universal as a parent’s undying love for a child who never grew up.

The search begins

It took me just minutes to learn Janet Lee’s last name, and to confirm that she had lived in Minneapolis. I found a message that had been posted in August 2016 to Ancestry.com, a popular genealogy website.

A woman, identified only as Kree, said Janet Lee was a distant relative from the American branch of her family, the Dahls. The woman said she wanted to know more about how the girl had died. “It’s just one part of my lost family history that I’m a little eager to put at rest,” she wrote.

In 2½ years, no one had responded. I posted a reply and sent Kree a message. Several days later, she answered.

“I’m afraid to say you’ve caught me at a bad time, but I’ll do my best to help,” she wrote in an e-mail. A native of the United Kingdom, she too is a collector of vintage photos, and a fan of Ransom Riggs. She also has a passion for her family history. Those interests, weirdly, came together when she got a copy of “Talking Pictures.” She knew from family lore of a girl who died far too young. Even though Janet Lee was Kree’s third cousin twice removed, her death left its mark on the far branches of the family tree.

I thanked Kree and shared the sparse obituary published in the Minneapolis Tribune on Aug. 20, 1959. Janet Lee Dahl, 10, had died “of injuries suffered in a fall.” She was an only child, survived by her parents, three grandparents and an aunt.

Now that I knew she was a local girl, I felt a new urgency to track down her story. I thought the “Talking Pictures” author might know more.

Ransom Riggs was intrigued to hear from me. He didn’t know about Kree’s post, but he knew Janet Lee’s last name, and that she lived in Minnesota, because the photos reproduced in “Talking Pictures” were only a fraction of the photos he had of her.

Riggs started collecting vintage photos in 2009, and set about writing the first Miss Peregrine and “Talking Pictures.” He got to know some of the “serious nerd photo collectors/sellers” who cater to the small market for old snapshots. One of them was Steve Bannos, a longtime TV and film actor. When Hollywood isn’t hiring, he supplements his income by selling vintage photos. He haunts flea markets and sells his best finds on eBay and at gargantuaphotos.com.

Bannos found the first part of the Janet Lee collection about 20 years ago in a Pasadena flea market. He first saw an image of the girl holding a Raggedy Ann doll, and thought he could sell it to someone who collected photos with a doll theme. A year or two later, at the same flea market, he found the rest of the collection.

I know that little girl, he thought. He flipped through the photos until the end. Then he wept.

Bannos had no intention of selling the 200 photos of Janet Lee. They possessed a “poignancy” unmatched by any of the 40,000 photos he’s sold. “There’s been nothing before or since that’s come to close to this,” Bannos said. “Nothing has ever come close to the Janet Dahl story.”

About a decade ago, Riggs went to Bannos’ home in Burbank to see his collection. Riggs told Bannos he could make a whole chapter in “Talking Pictures” with Janet Lee’s story. They made a deal. Riggs became, in his words, “the keeper of Janet.”

“I’ve never seen so many pictures of one person, with writing on every single one of them,” Riggs said. “Someone clearly loved this little girl, very much.” Riggs told me he had altered some of the captions to strengthen the narrative. Then, unbidden, he said he could send them all to me.

A life emerges

A package arrived in the mail a week later. The photos, stored neatly in a plastic box, were square, black-and-white, with scalloped edges and dates stamped on their borders. My daughter and I laid them out on our dining room table in chronological order. Janet Lee’s life began to emerge.

The earliest photos show Harold and Gertrude Dahl outside their home on Wilson Street NE. There are photos of Gertrude holding her 6-month-old daughter in the yard on a lush summer day. With his daughter in his arms, Harold even allows himself a smile.

Only seven photos survive from 1950 through 1954. In 1955, something changed.

Maybe Gertrude got a new camera. Maybe she realized something about the fragility of life. In 1955, there are 100 images. On a bitter February day, Janet is playing in the snow. In May, the family goes fishing. On Memorial Day, they visit Sunset Memorial Cemetery across the street from their backyard.

The next month, they take the Twin Star Rocket train to Texas, where Gertrude’s parents live. They play in the dunes on Padre Island and stay in a hotel in Monterrey, Mexico. In August, father and daughter walk through the woods to a dock for a fishing outing on Leech Lake. When Janet Lee smiles, you can see the gap where her baby front teeth used to be. This little family is having the time of their lives.

Over the next three years, the Dahls go back to Texas, and up to friends’ cabins. Janet Lee gets a little dog named Pal. She has friends, they play with dolls in the attic. Janet is growing taller, her face is getting more angular.

In May 1958, two photos of Janet, smiling but her face is disfigured. She had fallen again. On July 1, 1958, came Janet’s “little spell” at the Pointek cabin. She lies with her head on Harold’s lap, a bruise under her nose, and her hand clutching what’s probably an ice cube in a towel.

There are only 11 photos from 1959, but they contain the full arc of joy and sorrow of this extraordinary chronicle. As she turns 10, Janet Lee is reaching the beanpole phase of girlhood. She looks vital and healthy. That June, she’s back in Texas with her grandparents and visits her uncle’s grave. On the back Gertrude has noted that Janet died on Aug. 18 of that year.

I’m astonished by this caption. Why did Gertrude need to write that date? Would she ever forget it? Who was meant to read this?

I have trouble looking at the last images. A child should not be in a coffin. Yet she’s photographed from four angles. I was bewildered. If her mother took those pictures, was she trying to complete a story? Or was she numbed by grief and acting on instinct? The album ends, but I couldn’t let Janet Lee go.

So I turned to the files. I looked up the records of Gertrude’s estate in the Hennepin County Courthouse and found the name of the administrator, Leslie Ann Nelson. When I reached her by phone, Nelson told me she knew little about Janet, because she got to know Harold and Gertrude long after their child’s death.

Nelson put me in touch with someone who remembered Janet Lee. Now 87 and living in Salt Lake City, Bob Nelson was Janet Lee’s cousin. When he went to the University of Minnesota in the 1950s, he saw the Dahls. Janet Lee “was a nice, adorable little girl,” he said. “Her mother was very close with her. They took her everywhere.”

“I know she had some seizures,” he said. “She was born with some sort of neurological deficit.” He could see it in her unsteady walk. But that was all he could remember.

Through the estate papers, I found my way to Robert Gustafson, a retired professor and church pastor in Ohio. He and his wife, Yvonne, were eager to talk about their dear friends, the Dahls.

While the photo album ended with Janet Lee’s death, Gertrude and Harold lived on for decades. Harold was an engineer at Pure Oil. Gertrude taught art in the Minneapolis public schools. They worshiped at First Congregational Church, where they met the Gustafsons. Over the years, Gertrude mentioned a daughter who had died years before, though she wouldn’t say much about her.

“There was no doubt they loved and treasured that child,” Yvonne said. “The child was incredibly joyful and worshiped her daddy.”

The Dahls eventually became surrogate grandparents for the Gustafsons’ children. Robert e-mailed me a photo of his daughter on a rocking horse that had once belonged to Janet Lee.

Harold Dahl died in 1994, at age 93. Gertrude stayed in their home on Wilson Street until 1996. She died the following year. She was 92. I felt reassured that this couple weren’t defined by their loss. Because they didn’t talk about it, though, the details of Janet’s death were still a mystery.

I had to keep searching. The Minnesota Historical Society contains microfilmed death certificates going back decades. Sitting at the microfilm machine at the society’s library in St. Paul, I scrolled through the certificates until I reached Janet Lee Dahl. Cause of death: Subdural hematoma, or a bruise on her brain, from a “fall on floor.” The accident happened in her home. An autopsy was performed.

To my astonishment, the Hennepin Medical Examiner still had the report. Because it was printed on onionskin paper and bound in a thick volume, I would have to come to the medical examiner’s office and look at it. After signing me in, a clerk handed me the book. There, in cold typewritten words, was what I had been seeking for weeks.

Janet Lee Dahl was a girl with serious health problems: arrested hydrocephalus, a heart defect, “mental retardation” and a “convulsive disorder.”

“For a period of two years, she had had spells during which she collapsed on the floor, occurring as often as twice a day. She had had several head injuries resulting from these falls and on one occasion a skull fracture.” The medicines of the time had not worked for her.

“On the day of admission she struck the back of her head during a fall in the morning but was not unconscious. About 5:30 p.m., she had another akinetic spell and collapsed, striking her head on the floor.”

She never regained consciousness and died 18 hours later.

Gertrude’s documentary impulse makes sense to me now. She knew she could lose Janet Lee at any moment. I’m not sure I’ll ever find out how her photos ended up in a flea market stall in Southern California. Because they did, we are all the keeper of Janet now.

From her backyard, Janet Lee could see a line of wooded hills that marked the grounds of Sunset Memorial Cemetery. On an afternoon in early spring, I paid a visit to Sunset. I stopped at the edge of a large reflecting pool in the shape of a cross. There’s a photo of Janet Lee standing in that very spot on Memorial Day 1955, when she was 6.

Under the budding boughs of a hardwood tree, I found two stones set into the bare ground. Harold W. Dahl. Father. Gertrude D. Dahl. Mother. Then, a little farther up the hill, a greenish stone marker still wet with the morning rain. I brushed aside the leaves so I could read it.

Janet Lee Dahl. 1949 to 1959. One word in a circle: Daughter.

I know that little girl.