The Window That Wouldn't Stay Dirty

The atrium had forty-two windows, and forty-one of them were streaked with a summer's worth of dust.

"Look," Maya said. She pointed. "That one. Right in the middle."

Soren followed her finger. One pane, high up on the south wall, was so clear it looked like a hole in the glass. The forty-one around it were gray with grime and dried rain-spots. The one in the middle looked washed that morning.

"Maybe somebody cleaned it," Soren said.

"Nobody cleaned one window in the middle of a wall you need a lift to reach."

He considered that. "No. They wouldn't."

They had come to wait for Maya's aunt, who was a nurse and was always eleven minutes late off her shift. Waiting was Maya's least favorite thing. She had already read every poster in the atrium twice.

"It's warm in here," Soren said. He put his hand flat against the low part of the dirty glass. "The sun's really coming through."

"So why isn't the clean one dirty like the rest?"

Soren got out his notebook. He wrote down: forty-one dirty, one clean, all same wall, all same sun. Then he stopped writing and looked at the words.

"They're not all the same sun," he said slowly. "They get the same amount. But maybe they don't do the same thing with it."

Maya crouched to read a little brass plate at the base of the window frame. She had walked past it a hundred times. "There's writing here. It says the middle section was, um, replaced. Two years ago. Donated. New glass."

"New glass that stays clean," Soren said.

"Glass doesn't clean itself."

"This one might."

Maya stood up fast. That was the thing about Soren. He would say the impossible part out loud like it was just the next step.

"Okay," she said. "Say it does. How? Glass is glass."

A man in a gray uniform was pushing a cart of spray bottles past them. He had earbuds in and the tired walk of someone at the end of a long list of rooms.

"Excuse me," Maya said. "The clean window. Do you skip it?"

He pulled out one earbud. "That one? Never touch it. Boss says it's the fancy glass. Cleans itself when it rains. I think that's a story they tell so I don't have to get the lift out." He laughed and pushed the cart on.

"When it rains," Soren repeated.

"And when the sun's out," Maya said. "It's out now. And it's clean now."

Soren was flipping backward through his notebook. He stopped on a page with a cartoon sun and a squiggle of white cream. "Maya. Sunscreen."

"What about it?"

"My mom's got the white kind. The kind that doesn't rub in. It's got a stuff in it, titanium something. It grabs the ultraviolet in sunlight before it can get to your skin. Turns it into a little bit of heat instead. That's why it works even when it's smeared thick."

Maya's face did the thing it did when two pieces slid together. "The window's warm."

"The dirty ones are warm too, though."

"Then it's not just heat." She pressed her palm against the dirty glass, then reached up on her toes to touch the bottom edge of the clean pane. "Same warm. But this one does something extra with the light. It has to."

"The sunscreen stuff only catches the UV," Soren said. "It doesn't just sit there catching it. When it catches it, it gets, like, worked up. My mom's bottle says it can break things down. That's why some kinds go bad in the sun." He was writing now, fast, the pencil scratching. "What if the window's coated in the same stuff. Not to protect skin. To eat the dirt."

"Eat it."

"Break it apart. Grease, dust, whatever lands on it. The UV powers it up and it takes the dirt apart into little pieces."

Maya was already ahead of him. "And then it needs water to wash the pieces off. That's the rain. That's why he said rain." She turned in a full circle, looking at all forty-two windows. "So the sun does the taking-apart. The rain does the rinsing. And you never need a person on a lift."

"But there's no rain today," Soren said. "And it's clean."

They both looked up at the pane. A puzzle with a hole in it.

Maya found it first. She pointed above the window, to a row of little brass nozzles set into the frame, the kind that fed the planters along the top of the wall. A single bead of water clung to the lip of one nozzle, catching the light.

"The planter drip," she said. "It overflows down the glass. Every morning. Sun all day, water in the morning." She laughed. "It thinks it rains here every single day."

Soren looked at the bottle in his memory, the cheap white sunscreen his mom kept in the beach bag, and then at the towering clean window that used the exact same idea to keep itself spotless two stories up where no hand could reach.

"It's the same material," he said. "The same one. On your nose so the light can't hurt you. On the glass so it eats the dirt. Just standing in different places doing different jobs."

Maya was quiet for a second, which was rare. "Everybody walks past this. Forty-one dirty windows and one that's a little bit alive. Nobody even looks up."

"You looked up."

"You knew about the sunscreen."

The man with the cart came back through, and this time he stopped beside them and looked where they were looking.

"Huh," he said, taking out both earbuds. "You know, I never noticed the little water line."

High on the wall, the morning's bead of drip water finished its slow slide down the clean pane and let go of the bottom edge, taking the last of the invisible broken-apart dirt with it as it fell.