chekhov's gun

A boy who is stuck in a bus graveyard thinks that the stick in the hands of the Olympic runners is asthma spray. The boy starts chasing the runners to get the spray in order to save his sick father who has breathing problems, but he loses the runners. As a result of trying to find the runners, the boy gets on a bus that is different from the other buses. As soon as the boy gets on, he realizes that he is right in the middle of the Olympic arena and the runners are trying to come towards him.