We took our dog back to the humane society where we found him.

We took our dog back to the humane society where we found him.

Not to leave him there, of course. We would no more give up our dog than we would give up our frontal lobes. We took him back because the humane society was hosting an adopted animal reunion, and we thought it was time for Pip to discover his roots.

We arrived as the event was winding down. Even so, the place was swarming with dogs, some of them walking calmly with their owners, others insanely excited, to the point of doing accidental back flips on their leashes. Without delay, Pip joined the second group.

We parked the truck some distance from the center of the action, but Pip seemed to grasp the general idea from afar. I suppose his beagle nose was shooting him olfactory text messages: Dgs! Dgs! Ths wy! Tht wy! Lts rn!

My husband and I, meanwhile, were staggering across the grass, trying, as Pip strained at the leash, desperate to rn ths wy and tht wy, to look like people taking a pleasant Sunday stroll with their dog. Meanwhile, people who really were taking pleasant Sunday strolls with their dogs passed by, looking serenely unflustered.

At least, I reflected as my leash-holding knuckles turned white, I could dismiss my big worry. My big worry was that Pip would recognize the place where he had been caged and unhappy, conclude that we were taking him back, and fall apart with grief.

This didn't seem to be happening. Pip was thrilled with every person and dog he met, and many people and dogs were thrilled to see him.

"Look, it's Pip! Pip! Good old Pip!" humane society volunteers kept crying out.

Then they'd run over to rub his head and scratch his ears, as if Pip was Clark Gable, coming back to Ohio for a visit. As I watched people fussing over him and saw his delight, I began to wonder if Pip would fall apart with grief when we went home.

While we were at the humane society, we planned to look into the mystery of the disappearing microchips.

Pip had had a microchip inserted before we adopted him eight months ago. The chip is intended to identify dogs who have wandered away from home. When a scanner is passed over the chip, it reads an identification number, the dog is identified through an owner registry, and soon the dog is returned to his joyous and relieved family.

In Pip's case, though, it was the chip that wandered off. When someone scanned him, a routine check for adopted dogs on their way out the door, the chip wasn't there.

How weird, everyone said, but Pip was re-implanted and that, we all thought, was that.

The second chip disappeared too. Within days, my husband and I realized we couldn't feel it on Pip's lower neck, and we weren't surprised when repeated scannings at the humane society reunion confirmed our suspicions: it was gone.

Searching for the microchip became something of a party game as humane society people and microchip company representatives took turns with the scanner, running it not only across his back, but around to his belly, down his legs and even - though I'm pretty sure this was primarily for laughs - down his tail.

"It couldn't reach his heart, could it?" it occurred to me to ask.

The two or three people who heard this question all gave me looks. The chip's in the muscular system, they said, more or less in unison.

Ah, I said, nodding knowledgeably, as if I understood why the chip couldn't someday float right through Pip's left atrium.

This is very unusual, people said to my husband and me. Seriously, this never happens. These chips don't just disappear.

With a determination that circumstances force me to call "dogged," the technicians took Pip away for a third implantation. When they returned him a few minutes later, they made us all but swear to bring him back for a chip-check very soon. I'm not saying bets were involved, but more than a few people are interested in the results of that check.

As I write, Pip is about to report to the humane society. Once more he'll be wanded, if necessary from back to chest to stomach to legs to ears, nose and tail. If that chip has wandered off again, if it isn't found lurking somewhere on his black and white person, our dog will officially be recorded in the annals of veterinary history, and we can proudly introduce him as Pip, a textbook case.

Margo Bartlett is a ThisWeek staff writer: E-mail mbartlett@ this weeknews.com.