The Wrong Way to Make Ice

"We did it backwards," Maya said.

The two buckets sat side by side on the picnic table, and the porch light turned the frost on the table into tiny silver hairs. It was cold enough that Soren's breath came out in slabs. Twenty degrees below freezing, the weather app said. The kind of night that made metal doorknobs bite.

"We didn't do anything backwards," Soren said. "We filled them the same. Same buckets. Same water line."

"Not the same. I poured the hot into that one because the tap ran cold and I got impatient."

"So one's warm."

"One was hot. Steaming." Maya tapped the left bucket. "This one."

They had been out for forty minutes, coming back between rounds of hot chocolate inside. The plan was simple. Freeze two clean blocks, pop them out, carve them into something for the festival table. Cold water freezes faster, obviously, so the cold bucket would be their good block and the hot one would be the backup.

Soren leaned over the buckets with the flashlight. Then he stopped leaning and just stood there.

"Say what you're seeing," Maya said.

"The hot one has skin on it."

"What kind of skin."

"Ice skin. A whole sheet across the top." He moved the light to the right bucket, the one they'd filled cold. "This one's still just water. Cold water. Nothing on it."

Maya came around the table and put her finger on the cold bucket. It dimpled under her nail, all liquid. She put her finger on the hot bucket and it clicked, solid, a thin plate that didn't give.

"That's wrong," she said, and she was grinning when she said it, the way she grinned at things that were wrong. "That's completely wrong. The hot one's winning."

"It can't be winning. It started way behind."

"Tell it that."

Soren crouched until his eyes were level with the water lines. He tapped the hot bucket's crust with the flashlight's end. Solid tap. He tapped the cold bucket. Wet slosh.

"Okay," he said slowly. "Okay. It has more heat to lose. It has to travel further to get to freezing. So how is it there first."

"Maybe you're wrong about which was which."

"I'm not. I watched you pour the steaming one." He was quiet, then he said, "Do it again. Right now. So it's not a fluke."

They ran inside. Maya's mother was at the counter with her coffee and a stack of festival flyers she was supposed to be folding.

"How's the ice?" she asked.

"The hot water froze first," Maya said.

"Then you mislabeled the buckets, sweetheart."

"We didn't."

"Water's water. Colder is closer to ice." Her mother went back to the flyers, certain as a closed door. "You measured wrong."

Maya opened her mouth. Soren touched her sleeve, which meant let's just go prove it, and they filled two mugs, one from the hot tap running as hot as it went, one from the cold, and carried them out steady so nothing spilled.

They set them down. Marked the hot one with a twist of red thread around the handle.

"Now we watch," Soren said. "No going inside. If we go inside we won't know when."

So they watched. The porch light hummed. Somewhere a dog complained about the cold and gave up. Maya crouched with her chin on her knees and Soren held the flashlight steady on the two mugs, and for a long time nothing happened that eyes could catch.

"Talk," Maya said. "Or I'll freeze into the bench."

"The hot one's steaming still. Losing water off the top. Steam is water leaving."

"So there's less of it to freeze."

"Little bit less. Maybe. But not enough to explain it." He shifted the light. "And the hot water was moving. When it was hot it was churning around in the mug. Currents."

"So the cold sits still and gets a warm middle that hides."

"Maybe. And there's the stuff dissolved in it. Hot water pushes out its dissolved gas. The cold keeps it." Soren shook his head at his own list. "I'm giving you four reasons."

"You are."

"I don't know which one it is. I don't know if it's all of them. I don't know if it's none of them and it's something else."

Maya turned her head to look at him without lifting her chin. "You sound happy about not knowing."

"I'm not, I'm—" He stopped. "Okay. A little."

The red-threaded mug ticked. A small sound, like a fingernail on glass.

They both went down onto their knees on the frozen boards. Under the flashlight the hot mug had grown a lid of ice, cloudy at the edges, spreading toward the middle as they watched. The cold mug sat clear and liquid and beaten, its surface trembling only where the wind touched it.

"Second time," Soren whispered. "It's not a fluke."

"Tell my mom."

"Your mom would say we measured wrong again."

"My mom would be very sure." Maya breathed on her hands. "How many grown-ups have been that sure about this?"

"A lot. For a really long time." Soren sat back on his heels. "There was a kid. In Tanzania. Making ice cream in a school class. He said the hot mix froze faster and the teacher told him he was confused. His name got put on it later. Mpemba. The Mpemba effect."

"So a kid noticed and the teacher said no."

"And the kid was right. And." Soren stopped. "And here's the part. They still don't fully know why. Grown scientists. Right now. They argue about it. They run it in labs and it does it and then sometimes it doesn't and they can't nail down the rule."

Maya sat very still on the cold boards. "You're saying nobody has the answer."

"Nobody has the whole answer."

"The answer's just—out there. Not found yet."

"In a mug," Soren said. "In our mugs."

Maya put her face down close to the red-threaded ice so her nose almost touched it, close enough that her breath fogged the growing lid and cleared again.

"Do it a third time," she said. "Colder tap water. Hotter hot. Change one thing."

Soren was already pulling the notebook from his coat. He uncapped the pen with his teeth because his fingers had gone stiff, and under the porch light he drew two circles, and beside the left one he wrote hot, and beside the right one he wrote cold, and left the space beneath them empty for whatever the third try would say.