Luke, a curious fourth-grader, couldn't wait to start the school day. As he gathered his belongings and headed out the door, he realized his favorite backpack was missing. "Where could it be?" he wondered, searching high and low around the house.

Determined to solve the mystery, Luke enlisted the help of his two best friends, Jose and Ralph. Together, they retraced Luke's steps from the previous day, looking for clues that might lead them to the missing backpack.

After scouring the neighborhood, the trio decided to check the school. As they walked through the hallways, they noticed a strange-looking janitor hanging around Luke's locker. "That's odd," said Ralph. "I've never seen him before."

Sensing something unusual, the three friends decided to investigate further. They watched the janitor closely, and when he tried to leave the building, they confronted him. "Hey, what are you doing with that backpack?" asked Jose, pointing to the familiar-looking bag the janitor was carrying.

The janitor, caught off guard, tried to run away, but Luke, Jose, and Ralph were too quick for him. They grabbed the backpack and discovered that it was indeed Luke's, filled with all his school supplies. "You're the one who took my backpack!" exclaimed Luke, feeling relieved and proud of his detective work.

The janitor, now cornered, confessed that he had been taking various items from students' lockers and selling them for extra money. Thanks to the quick thinking and determination of Luke, Jose, and Ralph, the mystery was solved, and the janitor was turned over to the authorities.

From that day on, Luke, Jose, and Ralph became known as the "Mystery Solvers," always ready to investigate any strange occurrences around their school. Their friendship and teamwork had not only helped Luke recover his backpack but had also made their school a safer place for everyone.