"I know," I say to her. "I'm amazed myself."

"You're amazed?"

"Yes, I am."

"Why should you be amazed?"

"Well, I feel this friendly person coming out in me and I wonder if maybe that's my real nature. You know-the real me."

"Well, what is it that's changed exactly?"

"I'm on Zenax."

"I understand that," she says. "But what is it that makes you more friendly than before you took the Zenax?"

"Well, I'm not a particularly unfriendly person, am I?"

"Not now, you're not."

"No, I mean, I don't ordinarily think of myself as a sullen, bad-tempered kind of a guy."

"I didn't say sullen."

"Well-"

"You don't usually go out of your way to be chatty. Let's put it that way."

"Chatty?"

"You're chatting about the weather with total strangers. You never do that. Not as long as I've known you."

"Well, I thought it was kind of remarkable, don't you?"

"What?" she says.

"The weather. The change. The extreme difference between here and St. Paul in a matter of just three and a half hours."

"That's why people come here from St. Paul. The change in the weather. That's why we're here."

"Yes, I know that, but it's still remarkable, isn't it? A hundred and five here and minus thirty back there."

"Never mind," she says, and turns toward the slow-motion overhead fan.

There's a group of elementary-school teachers from Duluth right in front of us who suddenly burst into singing "When the Bear Comes over the Mountain" in perfect unison with no attempt at harmony. I guess the pulverizing heat and the waiting have tipped them right over the edge. The Mexican officials in SWAT Team uniforms look on in stony silence, arms clasped behind their backs, black Mayan eyes unmoved by this Nordic display of bravado. Our teenage kids have slumped completely to the concrete floor, heads propped on their backpacks, surrendered to the heat. They've stopped volunteering any conversation.

"Actually, I'm just glad to be alive," I blurt out after standing there awhile in a kind of stupor, hypnotized by the schoolteachers' ditty.

"You're glad to be alive?" she repeats in astonishment. "Is that what you just said?"

"Yes, I am. Just like Arnold Palmer."

"Arnold Palmer?"

"Isn't that what he says these days? Now that he's ancient; hobbling down the fairway. 'I'm just glad to be here. Just glad to be alive.' That's what he says when they run up to him with microphones and TV cameras, you know, for those golf show interviews. Even when he's having trouble with his putting, his swing. Isn't that what he always says now?"

"I have no idea. I thought he was dead."

"Arnold Palmer? No. He's very much alive. He's an icon."

"Whatever," she says and turns away again.

"Well, it's true," I continue. "I'm thrilled to still be here; back in the 'land of the living.'"

"I didn't realize you'd left us," she says.

"Well, that's the way I always feel when I've survived an airplane trip."

"Survived?"

"I always feel like I'm actually going to die when I get on an airplane. Like this is it, the end of the line; inevitable. Then, after we land and get back on dry land it feels as though I've lived through a kind of certain death and come out the other end. That's why I take Zenax and that's why I say I'm glad to be alive." She stares at me a second in absolute bewilderment, as though she's looking into the face of a total stranger, then turns back to the long stale line of humans in limbo.

"My God," she says. "What is taking so long with this customs thing? We've never had to wait this long before. What the hell is going on?" Just beyond the singing schoolteachers (who've now taken to doing the song in rounds, like Campfire Girls) is a somber couple I recognize from the Lindbergh Airport back in St. Paul. The man: in a wheelchair, somewhat older than the woman; late fifties maybe, blanket across his lap, a plaid scarf around his neck in spite of the stifling heat, and an odd alpine-style hat with a little brush sticking out of the band. The woman (his wife?) stands behind him, very erect, hands propped at the ready on the gray grips of the wheelchair, as though assigned to a permanent grim vigil. She is plainly pretty in a Midwestern open-faced, innocent way; wearing a light linen suit and white pumps-not exactly the expected attire for Yucatan beach life. The two of them seem completely detached from the goings-on: the silly singing; the constant fanning of everyone around them which has now become some kind of communal gesture of contempt for the Mexican bureacracy. Nothing seems to ruffle the couple's deep stoicism. Now and then, the woman slips a white handkerchief from her pocket and gently daubs the man's forehead and the corners of his mouth, although I can't make out any moisture. He doesn't seem to be suffering the consequences of a stroke or neurological disorder but rather a much longer and slower debilitation. Whatever it is, it's clearly taken its toll on the two of them.

Now, finally, the line begins to trickle forward. We prod our kids up off the floor and shove the luggage down through the roped-off alley-maze toward the customs inspectors. The abrupt, unexpected flow of the line seems to have caught the schoolteachers up short. They're scrambling for their baggage. The austere couple rolls silently on. The man's pale head slowly tilts upward, drawn by the tropical sunlight blasting through the tall arched windows of the main terminal. Each window frames an absolutely motionless palm tree outside. Heat waves brand themselves across the glass in vapored sheets. A single green parrot desperately wings its way from one palm to the next as though he might not make it; as though the savage heat might drop him flat in midflight.

We find ourselves crammed into a red Jeep Wrangler with a flapping canvas top. (The much larger Chevy Suburban I'd reserved having been let go due to our delay in the customs line. Mexico waits for no man.) My son immediately drops off to sleep, his six-foot-plus rail-thin frame crunched up in back with the luggage. Our daughter leans her head against the pipe roll bar, a T-shirt wedged between the steel and her soft temple. Thick jungle air pours across her face. My wife has gone completely silent now, staring up at a gigantic billboard of nearly naked brown twins coyly concealing their perfect breasts behind icy bottles of Corona. "Have you got a girlfriend?" she asks me out of the blue.

"A girlfriend?" I say, checking to see if our daughter may have overheard this but she too has been put to sleep by the heat.

"Yes, that's right. A girlfriend," my wife repeats.

"Where did this come from?"

"Don't act so surprised. You could very easily have a girlfriend and I'd never know it, would I? How would I know?"

"I'm sixty. Those days are over."

"Lots of young women are attracted to that these days. It's become chic or something."

"Attracted to what?"

"Older men. Men of influence."

"Men of influence?"

"Don't laugh. You know what I'm talking about."

"No, I don't have a girlfriend."

"How did I know you were going to say exactly that?" She stifles a little giggle, biting her lower lip.

"Could we talk about this later?" I suggest quietly.

"When?" she says.

"When we're not on vacation. When we're not riding down the Yucatan Peninsula with our children directly behind us."

"You do, don't you?" She smiles slowly at me with a look of supreme recognition then turns away toward the flying jungle. We pass a broken-down rock corral with ribby horses nosing through dust and their own manure. Blue patches of bottle flies blanket their eyes.

"Does this mean we're going to be silent and sour the whole rest of the trip?" I ask the back of her neck.

"We can be any way you want," she says without turning.

"Where in the world did this idea come from, anyway?"

"What idea?" she says.

"The idea that I have a girlfriend."

"It came from your cell phone, actually."

"My cell phone?"

"Yeah, that's right."

"My cell phone?"

"Are you going to just keep repeating yourself?"

"I'm repeating you."

"Yes, goddamnit, it came from your cell phone!" she bursts out. Both kids shift and grumble but never open their eyes.

"Could we talk about this later?" I say.

"That's something you said before too."

"I'm serious."

"I don't want to talk about it at all, actually. It's ridiculous. There's nothing to talk about anyway," she says with finality.

"So, you're just going to go ahead and believe in some crazy fantasy, some half-baked notion that popped into your head? Is that it?"

"It didn't 'pop' into my head, it came over your cell phone."

"What did?"

"A woman's voice."

"Oh-well, did you ask who it was? It could've been someone at the office."

"It wasn't 'someone at the office.' I'm familiar with everyone at the office and this wasn't one of them."

"It could've been anyone."

"Oh, please-"

"Well, it could've."

"All right, sure-yeah-right-it could've been anyone in the whole wide world, but it wasn't."

"I'm just saying-"

"Oh, shut up!" she suddenly shrieks. Our son wakes up with a jolt and snatches hold of the roll bar, waking his sister.

"What's wrong?" he pants, with his eyes popped out toward the road.

"Nothing," I say, "nothing. Just go back to sleep."

"What were you yelling about, Mom?" our daughter asks.

"I was yelling at your father."

"How come?"

"Because he's trying to deny he has a girlfriend and I've found out he has a girlfriend. Now go back to sleep."

"Great. That's really great," I say to my wife. "Congratulations."

"You're welcome," she says, and turns her entire back to me now.

Silence, except for the droning of the Jeep's oversize tires and the relentless jungle wind bashing the canvas top. The kids have burrowed back down into the luggage and returned to sleep. Her back is perfectly expressing expulsion. Exiled in the Yucatan.

"I might just as well have come down here all by myself," I say to her spine. No answer. We roar past Playa. Miles of fiesta-colored hammocks hanging in the heat; giant ochre pottery in the shapes of Mayan demons and once-sacred jungle creatures; jaguars, serpents, eagles, frogs. Everything's for sale on the carretera: rugs, serapes, Day-Glo wall hangings with lurid Aztec macho scenes; feathered warriors valiantly protecting young maidens from jade-eyed panthers. Huge billboards welcome us to the "Mayan Riviera" in English, as though Mexico were embarrassed to be Mexican. "I realize what it is now," I say out loud to myself but hoping she'll somehow respond. She doesn't. Her back remains a rigid blockade. The verdant jungle keeps rushing past. Now and then, a gap in the dense foliage. Daylight cracks through the tangle of vines and Chichin. Fleeting glimpse of an old man with his burro laden down with plastic milk containers filled from some secret cenote. Old sense of parallel lives. Separate. Haunted. I stumble on, just going on desperation now more than anything: "I think I realize now, what it is about the Zenax; how come I get so friendly on it." (I'm talking entirely to myself. The kids are snoring loudly.) "It's like with jazz musicians," I continue. "I remember all those guys down at the Five Spot in the sixties. They were all using smack back then. That was the drug of choice. I asked a drummer once why he was using it, and you know what he said?" (I don't know why I'm making a question out of this. Nobody's home. I soldier on.) "He told me he used it because it stopped all the inner chatter in his head. Isn't that amazing? It created a silence and then he could play."

For miles nothing happens. The mind goes on doing cartwheels; shuffling through its files, rewriting the past then tripping on some little tidbit of what it calls reason: "What were you doing answering my cell phone, anyway? I don't answer your cell phone, do I?"

"Because it was ringing," she says out of nowhere.

"I thought you were asleep."

"I'm not."

"I thought you were pretending to be asleep."

"I'm not pretending anything," she says, still offering only her flat back.