Pierce picked up his lunchbox, hugged his mom goodbye, and ran out to the bus station with his wet lunchbox. It was raining, and that meant that everyone's lunchbox was wet, so Pierce didn't notice.
Pierce finally got to school and went through the day until lunchtime. He noticed that there was no water bottle in the lunchbox, but that wasn't very odd; Pierce's mom was very scatterbrained. Then Pierce saw the empty vial and figured that it had fallen into his lunchbox.
Pierce peeled his banana and started eating it, noticing a strange tang in the flavor of the banana. He didn't think much of it, so he finished his banana. Halfway through his sandwich, however, which was in a ziploc bag, the entire cafeteria silenced. Pierce figured that there was going to be an announcement, but then he saw that none of the other students in the room were moving.
Then a warm feeling started at Pierce's feet, which kind of felt like warm water. It moved slowly up his body, and the areas it touched started getting tingly. It was up to his knees when Pierce looked down and saw how his shoes had disappeared and his feet were tiny.
Pierce immediatly looked down at his legs and noted with relief that his pants were still on, though the warm feeling was still moving upwards. It reached his crotch and felt a sucking sensation. Then the sensation reached his chest and shoulders. When the sensation touched muscle, Pierce noticed that most of the muscle turned to fat and moved to his chest, where two mounds were forming.
Finally, the sensation moved up to the top of his head, and Pierce knew that the changes on his body were complete.