The science cupboard door was jammed. Leo pressed his shoulder against the cold metal, but it didn't budge. A sour smell of old chemicals and dust seeped through the crack. He could hear Mrs. Chen's footsteps echoing down the hallway—she would be back any minute with the key. But Leo didn't have a minute. He had promised to return the beaker set before the bell rang.

"Come on," he muttered, rattling the handle. The lock clicked but didn't release. Inside, he knew, lay the glass beakers he needed for the afternoon experiment. Without them, his group would fail the practical test.

Maya appeared beside him, her arms crossed. "You locked it again?" she asked, her voice sharp. "I told you to leave it open."

Inside, he knew, lay the glass beakers he needed for the afternoon experiment.

"I didn't lock it!" Leo snapped. "It just stuck." He kicked the bottom of the door, and a hollow thud echoed. The metal vibrated against his shoe, sending a sting up his leg.

Maya sighed and knelt down. She ran her fingers along the edge of the door, feeling for a gap. "There's something wedged here," she said. "A piece of plastic, maybe." She pulled a ruler from her bag and slid it under the door. With a gentle pry, a small blue pen cap popped out and skittered across the floor.

Leo grabbed the handle again and turned. This time, the door swung open with a groan. A wave of warm, stale air rushed out, carrying the scent of dried glue and metal. Inside, the beakers sat on the middle shelf, gleaming under the fluorescent light.

"Thanks," Leo said, grabbing two beakers. He handed one to Maya. "I owe you."

Maya shrugged. "Just don't lock it next time." She smiled, and they hurried back to the lab, the beakers clinking softly in their hands.