I’m taking up some time on my extra bus trips lately — and reminding myself not to go to bookstores, because there is enough to read — by carrying my bus books with me. All right, one of them is new (Watch this space!), but I am also working my way through a series I’ve enjoyed since back in the previous century. That’s Laurie R. King’s series, commonly known as “The Beekeeper’s Apprentice” after its first volume, in which half-American orphan teenager Mary Russell meets Sherlock Holmes and becomes his apprentice.

I’m now re-reading “Justice Hall,” the sixth book in the series, for the first time in many years. (I occasionally check the front and see my signature and “Chicago 2002” in it.)

The story concerns a noble family, a mansion (excuse me, stately home) called Justice Hall, and the adventures of the family members, including a missing one, during the Great War. The story is set in the 1920s, as I find myself having to refer to that decade now, and the wounds of “the war to end all wars” are still fresh.

That’s what brought me to the headline’s question. Sometimes others have suggested to me that books — from holy scripture to much more mundane efforts — must have changed, because the person could not see something that now is obvious. I’ve held out, with logic I picked up in science classes, hours reading Holmes, or years around my dad, that books can be depended on not to change, apart from stains and other damage. It is the reader’s mind that perceives the text differently.

The story in “Justice Hall” brought that home to me powerfully today. Without spoiling anything, I can reveal that the detecting partnership of Holmes and Russell have found the diary of a missing member of the family they’re investigating. They found there tales of what this man endured in the trenches — which, back then, was a synonym for “the front lines.” The horrors he endured were explained by one of his companions, and they were so terrible that even Sherlock Holmes’ famous control of his emotions faltered.

But it’s harder for me to read this section today and look at my collection of family photos. I have one now that I didn’t have in 2002; I knew it as Dad’s grandparents, mother, aunts and uncles. But when I was practicing the text of “In Flanders Fields” for a concert honoring the centennial of the end of the Great War, I found myself reciting to that photo. The only clue I have to its date is what my dad said as he looked at his copy of it: “It must be before 1914, because the boys are there.” Both uncles died in the Great War, one in November 1918 (the month of the Armistice). They are my great-grandparents, grandmother, aunts and uncles. (I met some of my great-aunts and was introduced to them with the title Dad used, aunt; so my great-uncles, in my mind, are uncles.)

Gabriel, the diary writer in “Justice Hall,” was just a fellow diarist the last time I read the book. Now that he’s a fictional fellow soldier of my uncles, the story packs a greater wallop.

I am certain that I am the one who has changed — certain, and grateful.