I suspect that the story ending might make no sense to some. I will provide a spoiler explanation. Please do not read it until after you have read the story.
In order to understand this story, you need to know about the children's game Tag. In Tag, one person is chosen to be "It." In the simplest, most common form of the game, It's job is to tag (touch) someone else, whereupon the other person becomes It and the first person loses that moniker. The new It then needs to touch someone else (not the first It). The non-It children race around trying to avoid being touched by It. The game ends when everyone collapses from exhaustion or just grows bored. The game provides an outlet for the abundant energy of youth, and is a playground favourite in the United States.
I am guessing that a reader unfamiliar with the game would be confused by the ending. For that, I apologize.
I would love to hear whether the ending worked for you. In fact, all feedback appreciated.