My husband and I had no choice but to develop a form of heavily modified English spoken with the addition of various clicks and glottal stops. For a while, we thought we were deceiving her. Then one day she overheard us discussing, in our secret language, my spouse’s mother.

What’s histrionic personality disorder? our daughter asked.

Thanksgiving dinner was going to be a nightmare.

Our challenges were compounded by the fact that she spent most of her time at home. Montessori had expelled her after she proved—with beads and wooden blocks—the infinitude of primes, which badly upset the other children. Hanging around the house gave her plenty of time to learn our cant, and we soon found that, whenever she was within earshot, it was impossible to carry out the basic job of parenting.

Plus she was a sneak, a naturally gifted eavesdropper. She loved listening at keyholes and air vents, adored concealing herself behind curtains and under settees. She would leap out of hiding at the most inopportune points in our private conversations and insert her own frustratingly well-reasoned arguments. Desperately, we expanded our language to include the dative and genitive cases.

For her fifth birthday party our daughter demanded a lecture by an expert on Linear B script. We negotiated a fee—hiring the instructor ended up being cheaper than renting a bouncy castle—and he made his presentation. The party went off without a hitch, even if many of the parents of children in attendance suddenly remembered that they had appointments elsewhere and needed to leave early. But my husband was disappointed by our daughter’s reaction to his gift.

I thought every kid wanted Power Wheels, he said.

She had surveyed the miniature Range Rover coolly before wandering off to make cuneiform mud pies.

What did I do wrong? my husband wondered aloud. Am I a bad father?

So that night, during bedtime reading (Thucydides—for the millionth time), we delicately raised the issue.

You’ve been talking about that car for weeks, she said. Was I supposed to act surprised?

In her calmness, in her calculation and self-control, I sensed something alien, unknowable, unchildlike. I admit I shuddered a little. But we would not let ourselves be intimidated. Once again we changed our strategy. We were inspired by the Sinitic tongues to introduce a seven-tone system to our language. This allowed elaborate punning. For instance, the sentence, “Flu shots scheduled for next Wednesday”, could be communicated with the same phoneme repeated five times in a row but pitched differently in each instance. We supposed we were being clever.

As my husband and I planned family outings (we were not attending another quantitative analysis conference) or TV time reductions (her obsession with Michael Fassbender was getting out of hand) I’d glance at our daughter. She would glare back at me with narrowed eyes. I knew she couldn’t crack the code. It gave me a thrill to a taste a little of that sense of superiority most parents take for granted.

One afternoon, my husband and I were in the kitchen discussing whether we should all go on a trip to New York City. Our daughter was sitting at the dining room table working on some tricky problems in fluid dynamics. Since she was well within hearing range, we spoke in our lingua obscura.

My husband’s uncle was sick, and there wouldn’t be many more opportunities to see him. And we both wanted to show our daughter the city and make it a trip to remember. But money that year was tight, our schedules cramped. We decided it would have to be a whirlwind tour, limited to family engagements and perhaps a quick visit to Ellis Island.

From her spot at the dining room table our daughter chimed in, If we’re not spending at least a day at the Met, I’m not coming.

Her pronunciation was flawless. She pitched each tone with crystalline clarity. She even managed to pun the phonemes for at least a day and I’m not coming.

What choice did we have? We took out a line of credit. Our daughter later complained about certain curatorial liberties taken vis-à-vis the exhibit of Cycladic art.

At that point, we almost surrendered, but something drove us on. Was it hubris or was it fear? Whatever the case, our lives became a protracted battle for incomprehensibility. Our daughter kept growing and learning, and as she did it seemed that every time she went up a shoe size or mastered some new skill—Proto-Uralic, Dewitt evolutions, jump rope—she likewise mastered the latest version of our language. Again and again we responded by making modifications. Our speech grew hazy with the most timorous conditional tenses, it reversed and re-reversed subject-verb-object order according to a seemingly arbitrary set of variables. At one point it altogether abandoned nouns.

By the time our daughter was old enough to sleep without a night light, my husband and I were conversing in something like whale song.

Then, the year she turned twelve, our daughter demanded that we let her attend a season’s excavations at Göbekli Tepe. We had our reservations: air fare was prohibitive, the lead archaeologist’s methodology was suspect, and besides, was she really old enough to travel on her own to the other side of the world? I foresaw nights during her absence spent sleeplessly fretting.

Before we’d had a chance to make up our minds, our daughter came to us with a proposal. She said, Let’s sit down and discuss this like adults.

Recently I’d found, among her notes, a handwritten lexicon of cetacean verbs. She was on to us; our current system was bound, any day now, to crumble. As usual, it would take considerable effort to coax it through its next evolution. My husband and I were exhausted. Years of linguistic cat and mouse lay behind us, a long-fought campaign. It seemed the simplest approach would be simply to come to the negotiating table. So we did.

Our daughter made her case. We made ours. She offered concessions, which we rejected and then reconsidered. We put forward a number of proposals—and so on. It was indeed an adult conversation, a measured and rational dialogue.

In the end, we all agreed that she could go if she paid her way mowing lawns during the summer. Our daughter kept up her end of the bargain, sacrificing her usual hours of study for long afternoons among grass clippings and gasoline fumes. Finally, she set off on a flight for Turkey.

By the time she returned, she had received her first publication credit in a peer-reviewed journal.

Our language died. Mentally we consigned it to the Rubbermaid in the attic, to be stored alongside out daughter’s baby shoes, her newborn’s hospital bracelet, her first Pindaric ode. It hurt to see a part of her childhood fade and to recognize ourselves becoming parents of a teenager. But time healed the wound; we soon had other matters to concern us.

Before long our daughter discovered boys, and then girls, and then chalcolithic metallurgy. She went through adolescent mood swings and bouts of defiance, she attended her first formal, she joined the field hockey team, she set up a small copper foundry in the basement, she ran for school council as a democratic confederalist. At times, it was difficult. But as our daughter picked her way along the stony path to adulthood, our pride in her only grew: if she sat aloof at the heights of her intellect, we at least deserved some credit for raising her there.

At last the day came when our daughter graduated from high school. Despite many letters of acceptance and offers of full-ride scholarships—our mail carrier complained bitterly of the added weight to his load—our daughter surprised us by choosing a small, undistinguished university. We were at a loss; it made no sense. She refused to explain. And—as she pointed out—she had reached the age of majority; what could we do to stop her? Tearfully, we waved our goodbyes in the boarding terminal.

Time passed. Then one year, early in her academic career, just before she undertook her third Master’s Degree, our daughter came home for Spring Break. She brought her new partner with her.

Our daughter had never burdened us with details of her romantic life. From what we’d been able to glean, however, her infatuations and trysts were short-lived. We assumed that her immense brain led her to grow bored with potential soulmates, and that her changeable and ever-probing intelligence made it difficult for anyone else to keep up with her.

But recently there had been giveaways during our rare phone conversations—mentions of a “good friend,” occasional shifts from I to we when recounting past events—that suggested that an important individual, one unknown to us, had entered her life.

So we were thrilled when we learned she would be bringing her partner home to meet us. Who doesn’t hope that their children will one day find true love? We inquired about dietary restrictions—our daughter told us there were none—and then made reservations at a new Peruvian tapas restaurant downtown.

The big night arrived. It started off beautifully. I’m sure my husband and I were visibly nervous, but my daughter and her partner—a very sweet woman—were not. Introductions were made. We sat down to the meal, exchanged pleasantries, chitted and chatted. It was clear, by their besotted glances, their intertwined fingers, that our daughter and her partner were maniacally in love.

By the time the first ceviche tasting flight arrived, we learned that our daughter’s partner had no formal education.

Before we had taken the first bite, she informed us that she was a part-time dance instructor.

Never mind. We smiled tolerantly and lobbed the conversation in our daughter’s direction. She talked about her research; she’d kept in touch with the Linear B expert from her fifth birthday part, and was now working on his team decoding newly-unearthed inscriptions in Linear A. It was exciting work.

But as she held forth, my husband and I, rapt as we were, couldn’t help but notice the dance instructor’s eyes glaze over. Later, when our daughter recounted a historically-informed performance of Antigone she’d seen in London, the dance instructor brought up—without apparent irony—an episode of TLC’s Teen Moms.

The rest of what the dance instructor had to say isn’t worth recounting here. At one point, she described the healing properties of various crystals. I could tell by his tensed jaw that my husband was physically biting his tongue.

Our daughter hung on the dance instructor’s every word, eyes dewy with love.

We couldn’t make any sense of it. Yes, this dance instructor was beautiful (we supposed), she could keep small talk flowing in a charming fashion (we had to admit), and apparently she was helping our daughter “find her rhythm” (which couldn’t be a bad thing). But she was a complete moron.

Over dessert, our daughter told us they were planning to move in together.

The meal ended. We drove our daughter and her partner to their hotel. They sat in the back seat, and all four of us lapsed into post-prandial silence. My husband and I couldn’t help but exchange frequent, meaningful glances. We both had so much to say to one another. Was our daughter making the right decisions? Would the choice of a mentally subnormal dance instructor for a partner hinder her career? Was she trying to provoke a reaction? Make a statement? Get revenge?

Did she still love us?

In a flash, I remembered our old language and its final permutations. If I could summon it to my mind, my husband and I might exchange a few remarks sotto voce in the front seat. Just a word or two, anything to relieve the tension behind our sealed lips.

But my fluency was gone; I couldn’t even recall the basic lexicon. It was obvious, by the way my husband silently, almost imperceptibly moved his lips, that he was struggling, too—running through a table of baleen declensions, maybe—and having no more luck than I.

At one point during the trip, I met my daughter’s eyes in the rear view mirror. She looked happy. As usual, I had no idea what she was thinking.

Finally, once we were alone, my husband and I dove in. We picked apart every word exchanged over dinner, then tackled the big issues: our daughter, the dance instructor, our daughter’s future, our continuing duty to both support and gently guide our daughter, and just how wonderful our daughter was—even if, evidently, she hated us and wanted us to suffer. We spoke at length in plain English. And we were, as they say, of one mind.

Our daughter’s visit soon came to an end. The dance instructor had left town several days earlier for some sort of “workshop” she was running in “a really cool space.” My husband, my daughter, and I drove to the airport.

Tentatively, then delicately, then with considerable grace and good humour (given the circumstances), we, the parents, began to voice our concerns. It was lovely to meet the dance instructor, she certainly seemed like someone who could lead a dance class, and she likely had other talents, too. But our daughter—our daughter was still young; was she sure she knew what she wanted from life? What did she want, anyway? There must be other bright young women in her field who would love to meet someone like her, women able—no, let’s say willing to—let’s say—keep up with her. The dance instructor was a pleasant person, but—well, love was a sort of partnership, and a stable partnership demands equality—no, equal footing—no, let’s say shared interests—take your father and I, for instance, we’ve always—even when—anyway, what’s really important is to focus on—to use your time and energy—to consider—after all, what about—

As we drove, our daughter gazed out the window and said nothing. My husband and I kept talking, sometimes contradicting ourselves, sometimes repeating ourselves, interrupting one another as we both did our best to say what was on our minds, to make ourselves understood, to somehow, with our words, sway this force of nature, our beautiful daughter. And we kept talking—kept elaborating and then summarizing and then re-elaborating our main points—all the way to the airport, even after—long after—we both knew that, judging by her expression, she wasn’t listening to a word we said.