Two Lavender Magnets.

At the next science practice, Saeon went to the experiment bench. Sodam and Dure came, too. Teacher Gwak Doeun stood beside the case.

Last math practice, they had looked inside the trays. Even matching trays could hold different numbers of groups. Today, Saeon peeked inside first again.

A long observation case rested on the gray bench. Its clear plastic cover was closed at both ends. Two bar magnets lay inside.

“This time, they're both lavender.”

They were a different color from the gray bars last time. Both magnets were pale purple from end to end. Saeon stepped half a pace closer.

Dure opened the notebook on the shelf. The little result light on the front of the bench was off. The wide hallway behind them stayed open.

Each magnet lay in a shallow groove on a round holder. Two ends faced each other. The gap between them was as long as one magnet.

Outside the case were two round handles. The left handle turned the left holder. The right handle could turn its holder and move it closer.

The holders only turned when someone turned a handle. The bars could slide a little inside their grooves. They could not slip out sideways or turn by themselves.

Saeon opened a hand outside the case. There were no hand holes this time. A small white circle marked each end of each magnet.

All four circles were blank spaces for labels. An instruction display lit up, pointing beside them.

The teacher gestured toward both handles.

“Before you bring them closer, make a prediction.”

Saeon stood in front of the right handle.

“One at a time again.”

Last time, matching poles had pushed apart. N facing N left a gap. So did S facing S. Today, both bars were exactly the same color.

“They're the same color. They must be the same pole.”

Saeon pointed to the lavender ends in the middle, stopping outside the case. Sodam adjusted the arm of their glasses.

“A guess is still a guess.”

“I bet they'll push apart, though.”

Saeon's elbow lifted a little. They wanted to grab the handle and check. Dure raised an empty hand to chest height.

“Not yet. Look before you decide.”

Saeon lowered the hand. The handle was still at its starting point. Neither magnet had moved.

Amber light curled around the outer end of the left bar. Cloudy strands formed a small round knot. Two cream-colored gaps between them looked like eyes.

“Only the left one's tangled?”

Saeon checked the right bar, too. The lavender surface looked smooth. Its white label spaces were still uncovered.

The teacher pointed toward the left end.

“It's a device made from a mistaken idea. Tell me your reason.”

The knot stayed within the magnet's outline. It did not stretch toward the children. The handles outside the case and the hallway stayed as they were.

Sodam pointed toward the middle from outside the case.

“Do the facing ends have the same name?”

Saeon read the guide beside the left end. N. Beside the right end was an S.

The hand reaching toward the right handle stopped. The bars matched in color. But the two ends they would bring together had different names.

Same color. Same pole. Which one had Saeon been looking at?

Saeon brought the hand back. Last time, N and N had pushed apart, and so had S and S. Those were not today's two ends.

“It's N and S. I think they'll pull together this time.”

Sodam lowered the hand and watched the ends. Saeon looked at the middle gap, too. Now they could compare the prediction with what really moved.

“I'll leave the ends as they are. Just move them closer.”

Saeon slowly pushed the right handle. The right holder moved left. The space between the two ends grew smaller and smaller.

After the holder moved about a finger's width closer, the left bar slid right inside its groove. The right bar slid left, too.

The facing ends met. A short empty space appeared behind each magnet in its groove. Saeon stopped pushing.

“They're pulling together.”

Sodam pointed to the two ends from outside.

“N and S.”

It was not only the holder Saeon had pushed that had moved. Both bars had moved toward each other. Saeon checked the empty spaces behind them, too.

Then a shallow recess opened at the front of the bench base. Saeon let go of the handle. Dure brought their fingertips together outside the recess.

“The light's climbed this far.”

Inside was a little three-step stair piece. A line of light climbed along its rounded edges, a little higher than last science practice.

The top slot was still empty. Even where light reached, no stone piece filled the space. There were no letters or patterns.

Saeon kept their hands outside and watched the tip of the light. The upper slot at the math table had been full of light. Here, the line was still climbing below it.

The two pieces remained in their own places. Saeon left this one inside and memorized the empty slot. The recess in the base slowly closed.

When Saeon straightened, the magnets came into view. N and S were still touching. The knot on the left outer end had loosened, but it remained.

A thin band showed on the right outer end, too. Cloudy amber strands lay flat against the surface. They were so smooth that Saeon had missed them before.

“There was some on the right, too.”

Sodam pointed to each outer end in turn.

“The same Tangle wrapped around both.”

Saeon traced the boundary between the band and the bar with their eyes. The strands stayed inside the case. They had not grown while the children waited.

Sodam's finger returned to the middle.

“Let's keep the color and change only the ends.”

Saeon pulled the right handle back to its starting point. Stops at the ends of the grooves separated the bars. The original gap opened between them again.

The teacher watched the device from beside them. Dure took the left handle. Saeon let go of the right one.

Dure gave only the left holder a half turn. The left bar's outer end came to the middle. The right bar did not turn.

The left knot turned with its magnet. Now it wrapped around the end facing the center. It did not cover the white label space or the gap.

Saeon looked between the display and the ends. The right end was the same S as before. Only the left had changed. Now S faced the middle instead of N.

“The color's still the same.”

Sodam pointed to the middle gap from outside.

“Same starting gap, too. And push it the same distance.”

Dure let go of the left handle. Saeon took the right one. Starting at the same place, Saeon slowly pushed it just as far as before.

This time, the left bar slid left. The right bar slid right. The holders moved closer, but the ends did not touch.

Saeon watched the gap that remained. The lavender color was exactly the same. The bars had moved in different directions.

Sodam pointed one finger between the ends.

“Same color. We changed the facing pole, and the result changed.”

Sodam's fingertip moved from left to right.

“N and S pulled together. S and S pushed apart.”

Saeon followed the finger. Keeping the hand outside the case, Sodam continued.

“The color alone can't tell us which will happen. We have to read the facing poles.”

The outer strands of the left knot spread apart. The smooth band on the right loosened, too. One last strand remained on each magnet.

Saeon returned the handle to the starting point. The left bar stayed half-turned. Both bars rested with the original gap between them.

Letting go left Saeon's palm empty. Saeon read the names of the ends again, remembering what they had said first.

“I thought the same color meant the same pole.”

Saeon pointed to the S beside the right end.

“But it was N and S at first. I said they'd push apart just because of the color.”

They had seen two results with the same magnets. They had changed the facing poles and compared what happened. This time, Saeon looked at the names of the ends first.

Dure pointed to two lines in the notebook.

“Same color. Two results.”

Dure moved a fingertip to the front of the bench.

“Same starting gap. Same push. We've seen both cases. Finished.”

The finger swept once along the front edge without covering the result light. It stopped at the right end.

The final strands came undone. The light at both magnet ends faded to cream. The knot and band vanished inside the case.

Both lavender bars remained. The magnets themselves did not glow. Only then did the result light at the front come on.

Saeon looked up at the teacher.

“We saw them pull together and push apart.”

Sodam lowered the hand that had pointed to the ends.

“We kept the color and starting gap the same. We only changed which poles faced each other.”

The teacher waited for both explanations, then nodded.

“You read them well.”

Saeon stepped back from the bench and lowered the hand that had pointed only to the color. Dure shut the notebook and hugged it.

“Today's experiment, finished!”

The three friends followed the open hallway to the stairway door. They were still on the lowest floor. Beyond the door lay broad stairs and a railing.

Saeon stayed off the stairs and looked up. The upper slot was empty, but its light had climbed a little higher. Saeon imagined where that line might lead.

What was at the top?