"Excuse me?"

He cupped his hands around his mouth and spoke as if I were his deaf grandmother: "Trees...grow...back."

I cupped my hands around my mouth and said, just as loudly, "Not if the whole...damn...mountain is gone, they don't."

"Well, there's other mountains."

"Sure, there's some other mountains," I said, feeling that I might explode if I weren't careful. "If you got hit by a truck, Raymo, I guess your ma would say, 'Well, I have some other kids.'"

About half the class thought that was funny. The other half was probably trying to figure out how to get out of my classroom alive.

I stared them down, ticking like a bomb. "Sure. Trees grow back. Even a whole rain forest could grow back, in a couple hundred years, maybe. But who's going to make it happen? If you had to pay the real price for those jeans-the cost and the time and the work of bringing that mountain back to life instead of leaving it dead-those pretty jeans would have cost you a hundred dollars."

I felt strangely high. Furious and articulate. "Think about the gas you put in a car," I said. "The real cost. Not just pumping it out of the ground and refining it and shipping it, but also cleaning up the oil spills and all the junk that goes into the air when it gets burned. That's part of what it costs, but you're not paying it. Gas ought to be twenty dollars a gallon so you're getting a real good deal. But soon the bill comes due, and we pay it, or we eat dirt. The ultimate MasterCharge."

I can't swear they were listening, but they were watching me carefully. Thirty-six blue eyes ticked back and forth as I paced the floor in front of my desk.

"If Grace gets poisoned, if all these trees die and this land goes to hell, you'll just go somewhere else, right? Like the great pioneers, Lewis and Clark. Well, guess what, kiddos, the wilderness is used up." I walked around my little square of floor like a trapped cat. "People can forget, and forget, and forget, but the land has a memory. The lakes and the rivers are still hanging on to the DDT and every other insult we ever gave them. Lake Superior is a superior cesspool. The fish have cancer. The ocean is getting used up. The damn air is getting used up." I pointed at the ceiling, meaning to indicate the sky. "You know what's up there? Ozone. It's this stuff in the atmosphere that acts like an umbrella."

I stopped and reconsidered this effete analogy. Teenagers who won't use condoms aren't impressed by the need for an umbrella. I surveyed the class thoughtfully and demanded, "Whose Dad or Mom ever worked in the smelter?"

About half the hands went up, reluctantly.

"You know what they did up there, right? One way or another they were around thousand-degree hot metal. You ever see them dressed for work? They wore coveralls like Mr. Neil Armstrong walking on the moon, and a big shield over their faces, right?"

They nodded, relieved, I suppose, that I wasn't going to single them out for humiliation. I sat on the desk and crossed my arms. "Imagine that's you, working up there with that hot metal in your face. Now, somebody rips that mask off you while you're working. Goodbye face. Goodbye nose and eyelids, beauty queens. You're dead."

They might well have been dead, for all the sound they made.

"That's what the ozone layer does for us, boys and girls, it's a big face shield in the sky." I was skipping a few steps here, but not really exaggerating the consequences. Not at all. I attempted to lower my voice and sound faintly reasonable. "And it's slipping away from us. There's a big hole in it over the South Pole. When you use a spray can you make that hole bigger. There's something in most aerosol cans and refrigerators and air conditioners, called chlorofluorocarbons, that neutralizes the ozone. Factories are still making tons of it, right now."

I suspect "chlorofluorocarbons" was the largest word ever spoken within the walls of Grace High, and I'm fairly sure also that nobody forgot it for at least the rest of the day.

After the bell rang, Connie Munoz eyed me and said, "Miss, I seen you wear stone-washed jeans to school sometimes." The other kids were already out of there like bats out of hell.

"You're right," I said. "I didn't know about the mountains when I bought them. Just like Hector didn't, and you didn't."

"Yeah?" She chewed her gum and held me under a neutral, military sort of gaze. I'd publicly humiliated her new boyfriend; this would require some diplomacy.

"I've been learning a lot of this stuff just lately," I told her. "I'm not saying I'm not part of the problem."