"The Wish" is the third short story in Still More Tales to Give You Goosebumps.
A tweenaged boy named Max is locked in his closet by his obnoxious older brother Eugene, before trick-or-treating with his friend Alex. After they are finished, Eugene comes back and takes Max's apple and spills the rest of his candy on the street. Having nothing left, Max goes to the last house, where he meets a very old woman who forces a jagged rock into his hand for his treat. Max is about to throw it away, when she warns him not to throw away "the power". When Max gets home he wishes he were an only child before he goes to bed.
The next day he wakes up to find he is late for school, and that Eugene is gone. When walks to school he finds the building has vanished completely. He goes back to his house to find that Eugene's room has also vanished. When he goes to his friend's Alex house, but his mother screams when she sees him, and tells him to go away. he goes to the librarian, who reacts in a similar manner. He then goes to the grocery store, and when a clerk there sees him, he begins chasing him. Soon almost everyone in town is chasing him. He runs in desperation to the pet shop, where there is a woman he knows, who he hopes will help him. When he gets there she calms him down, but then hands him over to the crowd. He briefly sees the old woman again, who wags her finger at him, holding the rock she gave him. The crowd then puts him in a cage. Max the realizes that the rock granted his wish. The wish made him the only child on earth, and thus an endangered species.