Once upon a time, a girl and a boy were playing together and happened upon a secret laboratory. They entered and found a mysterious machine. They pressed a button and the machine shrunk the boy to the size of a marble. The children tried to reverse this action, but couldn't do it, and couldn't find anyone to help.
The girl picked up her friend and put him in her backpack, to take him home. The backpack was very disorganised and full of all kinds of things, and the journey home was just terrible for the boy, who couldn't help but cry.
When the girl tried to get him out of the bag, things were so jumbled that she couldn't find him. After many attempts and many tears, she decided to remove every object, one by one. Thanks to this approach she finally found her friend.
Both children learnt the importance of keeping things in order, even inside a backpack. The next day they went back to the laboratory, where a nice inventor managed to return the boy to his normal size.