You have to wonder at the sanity of a kid who decides to share a Disney World dream vacation with his three favorite caterpillars and a battered old teddy bear.

Unfortunately, I didn't notice those caterpillars until they were cruising at six hundred miles an hour, along with the rest of us on our flight to Orlando in central Florida.

"Joel!" I don't know how many times I've had to hiss that word in a low whisper.

He raised his eyebrows in hurt shock. He's had practice at that, of course.

Joel's my six-year-old brother and haunts me worse than any ghost. I'm twelve, but he terrifies me. Somehow he appears and disappears when I least expect or want it. Walls and locked doors don't stop that kid. When I do spot him -- which is rare -- he says nothing. Only stares at me with solemn eyes that take in exactly whatever I'm doing at that moment, which usually happens to be something I want nobody in the world to see. Then, as I'm bursting out of my skin with terror at his sudden appearance, he's gone again.

That's why I had breathed relief to see our seating arrangements on the plane. It was a full flight, and since none of us had been able to sit together, Joel was left of me -- across the aisle and firmly and safely wedged between two large grownups.

I had the aisle seat on my side, with an old lady and her husband on my right. The old lady's hat was so wide that I could barely turn my head to look across her out the window. Other than that, it was a good seat. Far enough away from Joel for freedom, close enough to watch him. The rest of us -- Lisa Higgins, Mike Andrews and Ralphy Zee -- were scattered throughout the plane.

But now as I looked over at Joel, I stifled a groan. Joel was still playing with the jam jar he had smuggled onto the plane beneath his jacket. The jar contained a few leaves and some stems of grass, and, of course, his three favorite caterpillars.

Great.

"Joel!"

I couldn't hiss too loud. The guy immediately to my left, in the opposite aisle seat -- directly between Joel and me -- sat with his chin slumped into his chest. Asleep. And he didn't look like the kind of guy you wanted to wake.

He was so big that his knees crammed upward between him and the seat in front. All I could see in profile was his huge wedge for a nose and the way it hung over a thick and drooping walrus mustache.

"Joel!"

It didn't work. Joel smiled and shrugged and held his jar in front of him and admired his friends inside. He set the jar sideways and shook it, just to make the caterpillars topple over each other and fight for balance.

"You look nervous, sonny. Scared of flying?"

I jumped an inch off my seat at the unexpected voice in my ear. Even away from me, Joel still finds a way to scare me.

"No," I replied to the old lady on my right as soon as I could breathe. "It's just that--that--"

How do you explain Joel to someone who doesn't know about him? Especially since he had just tucked the jam jar out of sight.

"Yes?" she asked, wrinkles squinted in question marks.

Change of subject needed.

"It's only an hour before we land," I said, giving her my full attention. "Will you be visiting Disney World?"

Her puzzled frown broke into a delighted beam of false teeth as she nodded proudly. "Our first time," she said, pointing at her husband beside her at the window. "We've heard so much about it from our grandchildren that we absolutely had to see it for ourselves."

I smiled with her. Disney World and Easter holidays. Our gang had waited forever for this!

To pass time, I explained to the lady. How once before -- a week away from leaving -- a desperate phone call from New York had made us postpone our trip to Disney World. How, after his son had been rescued, a grateful and wealthy father had insisted on paying for this vacation. How he had arranged for his chauffeur to be a chaperone for the next few days until our parents arrived to join us. How --

Joel!

From the corner of my eye, I saw what I didn't want to see. Joel was unscrewing the lid of his jar.

I froze.

The old lady's husband asked her a question, and she turned to him. Which left me alone and helpless to stop Joel.

I glared at him. He smiled again and shrugged again and lifted the lid clear of the jar.

I raised my top lip in a silent snarl. He pouted, but did not replace the lid.

I clenched a fist and slowly raised it in his direction. That worked. Joel began to move the lid back to the top of the jar.

And the plane hit a pocket of turbulent air and bounced down. Only half a foot. But that was enough.

I think it was the surprise of that slight drop. Joel overreacted as he juggled the jar. The rest seemed to happen in slow motion.

Joel's eyes widening in surprise. His hands popping upward. And leaves and caterpillars shooting from the open mouth of the jar.

I groaned.

The old lady beside me asked for the napkin on my lunch tray.

"My husband just spilled his coffee," she explained. "Turbulence." As if I didn't know.

I barely remember handing her the napkin because my eyes were riveted on upcoming disaster.

One of Joel's caterpillars -- naturally the biggest and greenest one -- had landed on the big man who was still asleep in the aisle seat between us. Not only that, it had landed on the man's right shoulder. Out of Joel's sight and out of Joel's reach.

"Joel!" I hissed yet again.

He ignored me in a frantic search to recover the other two caterpillars.

The third one inched toward the big man's neck.

It about killed me.

One monstrously sized man in a dark suit so old that it was back in fashion again. One huge green caterpillar creeping onto a shoulder so big it strained against the threads of that suit. And me, the only person aware.

I mentally screamed at the caterpillar to reverse direction and head back down. No surprise, that effort didn't work.

The old lady beside me fussed over her husband's shirt front. As if that was the most important crisis.

My blood slowly turned into lumps of fear. The caterpillar made a determined march onto the man's thick neck. He twitched slightly and grunted, but did not wake.

I knew I didn't have much time. Joel was too busy searching for the other caterpillars, and this one was rapidly getting within range of that slicked down mustache.

All I could think of doing was to grab the inflight airline magazine. Maybe I could just roll it into a baton and --

I gasped. The caterpillar was already on the man's broad cheek and racing for his mustache, the closest thing it had seen to a leafy branch since leaving home.

I would have to reach over with my rolled up magazine and flick the caterpillar away with the utmost speed, and with enough delicacy not to hit the man's face

Without daring to stop and wonder at my craziness, I reached across the aisle. I brought back the magazine to give a quick flick and -- the huge man woke just as the caterpillar explored the hairs of his right nostril.

I tried stopping my swing, but it was too late. The man had jerked forward in surprise as he woke. My gentle flick became a solid blow across the man's nose and forehead.

He opened his mouth to roar outrage and the caterpillar dropped inside. The man clamped his mouth shut in surprise.

So far, everything had happened in silence. The next moments were no exception.

His eyes popped wide. We stared at each other. Then, slowly, I dropped my eyes to look down at the man's lap where half a caterpillar squiggled its yellow guts on the dark fabric of his suit.

He followed my eyes downward. Then turned a chalky white. It didn't take a genius to guess the location of the other half of the caterpillar.

I did the only thing possible. I offered the man my airsick bag.