Write a mystery short story with four paragraphs and it be school friendly with 5 sentences in each paragraph

Once upon a time in a small, peaceful town called Oakwood, people were abuzz with excitement for the upcoming annual science fair at Riverbend Middle School. Students spent weeks preparing their best projects, hoping to have their work showcased in the school hall for all to see. As the day of the fair approached, tension and anticipation grew amongst the students. Who would be the winner this year? Little did they know that a perplexing mystery was about to unfold with the disappearance of a very important science project.

Johnny Baxter, one of the most brilliant students in Riverbend, had been working on a top-secret experiment that he believed would win the science fair. His creation was a remote-control robot that could both open doors and lift small objects. It had the power to potentially change the lives of people with physical disabilities. Close to the day of the fair, he practiced with the robot one last time before placing it inside a locked cabinet in the school's science lab. He then went home, eager to unveil his masterpiece the next day.

On the day of the fair, an anxious Johnny rushed to the science lab to fetch the robot, only to find the cabinet wide open and his invention gone. Panic set in as he frantically questioned his classmates about the whereabouts of his robot, but no one had any idea where it could be. The science teacher, Mrs. Jones, tried calming him down while suggesting that perhaps he misplaced it or accidentally left it at home. But Johnny was adamant that he had locked it away in the science lab. As all the students gathered in the school hall, Johnny embarked on a desperate search, determined to find his robot and reveal the thief.

While Johnny was searching for his robot in the school, he noticed some unusual, unfamiliar footprints around the janitor's closet. Curious and excited about this new clue, he followed the footprints only to discover some traces of oil leading to a storage room. Pushing the door open with bated breath, he found the robot hidden amidst old school supplies. Johnny grabbed his project and went straight to Mrs. Jones. She announced the discovery to the entire school and praised Johnny for his determination and quick thinking. Although the thief was never uncovered, everyone learned a valuable lesson that day - mysteries can be unlocked with dedication and perseverance. And as for the thief, well, they probably learned it's best to respect other people's work, especially when it's for a middle school science fair.