My Labrador Retriever Harper is a dog of many talents, not the least of which is the ability to sniff out a single slice of pepperoni in a hermetically sealed container buried six feet underground on a distant continent. (Okay, he’s never actually done that, but it’s a safe assumption he could.) His true superpower, however, is his keen ability to detect a barely cracked-open door from three floors away and shoot out of it at lightning speed, with zero intention of ever turning back.

Knowing his vagabond nature—we adopted him after he’d been found roaming the streets—we are vigilant about closing all doors, gates, and dryer vents. Even so, Houdini Harper has managed a handful of successful getaways in the past nine years. Each one has ended with him panting and proud and one or both of his humans panting and plenty p.o.-ed.—not to mention, variously covered in mud, leaves, or twigs, and on one memorable occasion, dripping wet from diving in a lake after him. The only time we were able to retrieve our retriever in short order was when a neighbor corralled him in her open garage where he’d made a pit stop to eat the entire bowl of her cat’s food.

Thus, you can see Harper was not exactly cut out to be a caretaker. Little Timmy would have shriveled up and died in that well if he’d had to depend on Harper to run back to the farm for help. Yet, when push really came to shove, Harper quite astoundingly summoned his inner Lassie and assumed the mantle of responsibility to prevent a terrifying situation this past summer.

Our son, daughter-in-law, and adorable four-year-old grandson Lucas, were visiting us in suburban Atlanta all the way from Doha, Qatar, where they’d been transferred a few years before. Our grandson had been in our house exactly one time before, the previous year when he was only three. In addition to being in unfamiliar surroundings, he was politeness personified and wouldn’t even take a cracker from the pantry without asking permission.

Never did any of us imagine that while I was at work and the other three supposedly responsible adults were engaged in household duties, little Lucas would take it upon himself to quietly unlock and open the front door and take Harper, a.k.a., the runaway train, out for a potty break.

The first clue the adults had that anything unusual (and potentially disastrous) was afoot was hearing Lucas call out calmly but insistently, “Mommy, open the door.” With equal parts shock and panic, they realized the voice—unlike those in horror movies—was coming from outside the house. Hearts pounding, they raced to the front door and swung it open wide, but found no Lucas on the doorstep. Just then came another firm request. “Mommy, open the door.” Running to the driveway, they saw Lucas standing on a neighbor’s porch two doors down. And standing right beside him, stock-still, was an off-leash Harper.

Lucas had apparently gotten confused after his and Harper’s little jaunt around the cul-de-sac and had returned to the wrong front door. When he and Harper saw my son-in-law running to them, both casually turned around and started walking, side by side, back to our house—the whole time with Harper acting as if this were his normal M.O., as if he hadn’t run wild over hill and dale every single other time he’d escaped captivity.

When the adults’ blood pressure finally returned to normal, they asked Lucas why he had done such a scary thing. Lucas shrugged and simply explained he believed Harper needed to “go,” and since the adults were busy, he took matters into his own hands. He further commented that the lock on the front door wasn’t very hard to figure out. So, you know, no big deal.

Of course, the truly amazing part of this story is how Harper stuck by Lucas the whole time. If he’d taken off to hither, thither, and yon as per usual, Lucas would likely have chased after him. We shudder to think how badly that could have ended. It was as if Harper instinctively knew he had to protect Lucas. Harper, a responsible custodian—who woulda thunk it?

Grateful for the happy ending, everyone settled in to watch an episode of, appropriately enough, “Paw Patrol.” Lucas got a cookie and a serious talking to about never opening the door or going outside without an adult. Harper got a cookie, too, and a few extra belly rubs. Lassie may have been a famous Hollywood star, but around here, Harper the Hero is definitely the top dog.