This reversal of Boston — no dog parks, just cafes — was disorienting to Edgar and me, both of us now in early middle age, our timelines crossing there in Paris. So we marched up and down the Seine, his leash hooked to the stroller, and we discovered that the beagle’s natural prey is not the rabbit, but the baguette.

I have no shortage of non-dog memories from Paris, but the chronology clarifies itself instantly when I remember this: whenever we came home, even in the hottest, most unconditioned air, Edgar still ran up the three flights of crimson-carpeted staircase to our door, his back legs propelling in unison, like a dwarf kangaroo. But, only a single summer later, when we had moved our growing family to the coast of South Carolina, Edgar walked upstairs one leg at a time.

He and I forged a new summer routine on the Atlantic Coast, more suited to a dog of later middle years and his suddenly younger human. The extreme heat allowed us outside only early in the morning and late in the evening, and then we walked on the beach.

Edgar, beach, sunset: and at once I have those summers in detail. We wandered the shore, confident without a leash, and I would occasionally slow down for my friend, now definitely older than I, while (and you’ll have to trust me) dolphins arched and leapt not 30 feet from our wet bare feet and paws. A pod of four to six would, on some fine nights, keep unlikely perfect pace with us, matching our step for a mile or two.

Because of new zoning laws that require all novelists to live in Brooklyn, we moved to the borough a few years back, my two children, my wife and our elderly dog, Edgar.

Despite all the evidence of passing time (my younger boy could talk, my older liked school, I was writing my third novel), nothing brings back that first New York summer any faster than the memory of Edgar not terribly interested in the dogs at the dog park near our home, and the summer after that, him slow with cancer, an old, old fellow with no interest in much of anything but trying to find a comfortable position on the couch.

That same pup who had, 11 summers before, blessed my betrothal in the tall grass of the Boston suburbs, I now carried in my arms the six blocks from our Brooklyn home to the veterinary hospital where the final kindness I could do my old friend at the end of our last walk was to give him the injection that made his tired body kick, then shudder, then sleep.