We watch for a while, but then we move on. All three of us try our hand at juggling and archery (without much success), and we make messy brass-rubbings of knights in chain mail. The boys are wired. They’re bored. They’re excited again. They really go crazy when a raggedy man who identifies himself as the Groveler hurls himself at my feet, beseeching “milord” for “a bit of silver.” Seizing an ankle, the mad actor sends the boys into a delirium of grossed-out laughter when he actually licks one of my dusty Tevas. Then smacks his lips, as if savoring the grit.

So it’s a blast – or at least it is until I reach for my wallet to pay for snow cones and find that it’s not there. My mood goes into free fall as the coming hassles stack up in my head. I’ll have to replace all my IDs, my credit cards, my driver’s license. Is there enough gas in the car to get us home? I keep an emergency twenty in the glove compartment, but I spent it a couple of days ago at a pizza place that didn’t take plastic. I don’t even have any change – I gave it all to the Groveler.

We retrace our steps – and then Kev, walking behind me, finds my wallet. “It’s in your pocket, Dad,” Kevin says. When I reach back for the wallet, Kevin says, “Nuhuh, the other one.”

And he’s right. There it is. I pull it out. “Duh,” I say, “in my pocket. Why didn’t I think of that?”

The boys respond with a nervous laugh. I’m left shaking my head. “I always keep my wallet back here.” I slap the back pocket, left side.

“Not this time, I guess,” Sean says.

“I guess not.”

It seems strange to me that I would change the habit of a lifetime, so strange that I open the wallet to check. “Looks like everything’s here,” I tell the boys. “And you know what – feeling stupid is a big step up from the way I felt when I thought I’d lost it.”

“So let’s gooooooo,” Sean bellows.

“To the joust, good sir!” adds Sean.

And so we’re off to the pièce de résistance of the waning afternoon. The boys have been hectoring me for the last hour about this, Kevin checking the time every ten minutes. The jousting match is scheduled for four-thirty. As we turn down a lane and enter the amphitheater, I can see that it’s good we came when we did. There’s already a big crowd gathered; we have to sit quite a way back from the action. The seats consist of bales of hay, arrayed on the shallow concentric tiers surrounding the central arena.

The joust involves four knights, decked out in full armor. As they prance around the ring on their beautiful horses, presenters dressed as squires work up pockets of support for the different contestants. Each part of the arena sports flags and pennants of a different color – red, green, white, black – and these match the colors worn by the knights and their respective mounts.

We’re sitting in the green zone. Each squire rouses support in his section by cuing the crowd for cheers and leading it in taunts. “The Black Knight is a clumsy oaf. Together now…” As part of the buildup, young well-wishers for each knight are summoned forward to the fence surrounding the ring.

The boys clamor to join “the Green Machine,” a band of children assembled to cheer the Green Knight. I hesitate.

Liz would never let them. She knows she’s overprotective – she even worries about it. “I know it might make them feel insecure,” she admits. “I’m sending the message that the world is full of danger.” But she can’t help herself. Even I have been the focus of this kind of worry. I used to love rock climbing, for instance, but Liz just hated it. After the boys were born, she begged me to give it up. I didn’t put up much of a fight. I saw her point, for one thing, and for another, I was so busy at work by then I didn’t really have time for it.

As for the boys, it’s worse. She can hardly bring herself to let them get into another mother’s car for the car pool without checking the seat belts, the car seats, the car’s safety record, the driver’s apparent skill.

“Daaaaad, please.” Down in front, the green squire is handing out emerald pennants and green balloons. The “Green Machine” kids wave the pennants, jump up and down. I tell myself this is exactly the kind of thing they should be allowed to do. I’m right here, after all; I’ll be able to see them. What could happen?

I give in and enjoy their exuberant delight.

“Okay! Let’s go!”

“Yesss!”

I watch their blond heads bob down the aisle as they make their way toward the fence to join the cheering throng of children. The squire hands each of them a green pennant. Then the joust begins and, to my surprise, the horses are as spirited as they are large. You can sense their power. The ground seems to tremble as the red and white knights charge, leaning over their lances, eyes locked on each other’s hearts. When the riders come together, the clash is loud and violent. A roar goes up from across the arena as the Red Knight tumbles from his mount and goes sprawling. The White Knight plants a kiss on his lance and raises it into the air. The white cheering section goes crazy. I check for the kids and spot them toward the right of the cheering section. Along with some other children, they’re petting a little dog. Even the dog is in costume, wearing an Elizabethan thing – a ruff – around its neck.

All eyes return to the arena as a trumpet heralds the next match. Green and black charge toward each other. After a tremendous collision, the Black Knight crashes to the turf. Even I have to admit it’s exciting. These are real jousts, and I’d be surprised if the riders didn’t keep track of winners and losers. When the Black Knight gets to his feet and slinks away, rubbing his backside, it’s impossible not to applaud.

This is great, I’m thinking, and turn to see how the boys are liking it. My eyes go to the fence where the Green Machine is gathered, but I can’t find Kev and Sean in the crowd. Not at first, anyway.

And then: I really can’t see them.

Getting to my feet, I crane for a better view. People behind me start yelling “down in front.” I ignore them and continue to look. But the boys – they just aren’t there. A sizzle of panic surges through my chest. I suppress it.

In the arena, the victorious knights prepare for the final joust, their horses at either end of the arena, pawing the ground and shaking their massive heads. The green squire leads his kids in a chant. “Green! Green! Green! Green!”

“Kev?”

I tell myself they’re right there, right in front of me somewhere, but hidden behind some older, taller children.

“Sean!”

The squire is leading a new cheer – “Gooooooooo Green” – as I work my way through the crowd, down to the fence. “Kevin?” I raise my voice, so that I’m shouting louder than the cheering.

Arriving at the fence as the Green Knight charges toward his opponent, I realize that I’m more terrified than I’ve ever been in a war zone. “Sean?”

I’m shouting at the top of my lungs now, and looking wildly around. And I see: other kids. Lots of them. The Green Knight goes down and a disconsolate moan ripples through the section while a roar erupts across the arena. At the bidding of the squires, balloons are released en masse. I push my way to the fence and scan the mob, searching frantically for blond hair, a yellow T-shirt. I can’t see them. Kids begin to disperse, skipping back toward their parents.

After a minute, I return to the approximate hay bale where we were sitting. I fasten my eyes on the dissolving crowd, willing it to reveal my sons, but after a few minutes, except for a woman a few rows down soothing her screaming toddler, I’m alone.

It’s five-twenty-two in the afternoon, and the twins are gone. Gone. I sit there hoping the boys have gone to the restroom and will soon be back, but I have a terrible feeling in my chest. I know they didn’t go to the john. Not without telling me. Not in the middle of the joust.