Some grandparents remember their grandchildren’s early years as a kaleidoscope of blocks, plastic stacking rings, sticky highchair trays, and cars named Doc Hudson, Lightning McQueen and Flo. What I remember are book characters: Davy the sheep from Matthew Cordell’s Another Brother, the doleful rodent in Robert Kraus’s Whose Mouse Are You?, and James Marshall’s all-too-human hippos, George and Martha.

Dozens of family photographs show my three grandchildren listening to someone read. Often, I’m the one holding the book,  but that’s because we were less likely to be there, clicking our phone cameras, when the kids’ parents snuggled up to read, or these children were with other loving relatives who also knew Kevin Henkes’s Sheila Rae, Wemberly, Lilly (and Lilly’s teacher, Mr. Slinger), Quentin Blake’s Mrs. Armitage, and a whole crowd from the head of Drew Daywalt, including Rock, Paper, and Scissors, and Huggie and Stick.

The kids grew, as kids are wont to do. They finished kindergarten. They learned to read. They discovered Jeanne Birdsall. Ben Hatke. Sara Pennypacker. Rick Riordan. I read — and loved — many of the books, but in no time, I was reminded of my running story.

I started running when my older daughter was in middle school. I bought a family pass at the local university’s athletic facility, and my two daughters and I would go there frequently. While I eked out the miles, they’d amuse themselves with short sprints and horseplay. Later, we’d all hit the pool.

During those early days, my older daughter made her contempt for running clear. (She was, as I say, in middle school. She made her contempt for anything, which was practically everything, clear.) She would never run, she said. Borrrrrring.

Then she did run. I can’t remember why or when she started, but she ran throughout high school and has been running ever since. We’ve often run together. At first, I slowed down for her. But very soon, her pace improved, and in no time, she was slowing down for me, an arrangement that endured.

Now compare this to my reading grandchildren. At first, adults — parents, grandparents and teachers — led the way. Then the kids learned to read, and soon they were mere specks in the distance, gulping down books we’d never heard of, referencing series we’d never come across.

Early on, I began bracing myself for the inevitable. The era of cozy reading sessions will end, I told myself. Indeed, it has ended, in the case of my granddaughter. She and her mother still read together, but mostly she reads on her own. I can’t complain and don’t want to. She’s a reader. That was always the goal.

My grandsons also read like they breathe — in the car, at the table, while walking from the parking lot to the ballfield and back again, eyes on their books, their bags of gear banging against their legs.

I trailed behind them this summer as they raced into the Bozeman, Montana, library, where they collected a heaping pile of books and checked them out on a new library card. The books sustained them through ten days in the Yellowstone and Grand Teton national parks. The night before our flight home, we returned the books, each of them read, some more than once. The days of reading aloud, it seemed, had well and truly ended.

Except they hadn’t. Recently, at their house, I picked up a book once owned by a child who is now these boys’ uncle — The Black Book of Secrets, by F. E. Higgins. I began reading aloud during a moment of wild carousing, and within minutes both boys were beside me on the couch, listening to narrator Ludlow Fitch describe a terrifying assault and his escape to the tiny village of Pagus Parvus, where his story begins.

Now, whenever we’re together, we get in another chapter or two. Recently, we devoured seven chapters at once. Since then, they may have read ahead, but I doubt it. The Black Book of Secrets is our project, and the best part is, Higgins has written several other books.

We have a lot of suspense ahead of us.