“Will you shut off the house sometime soon?”

“We’re considering it.”

“I don’t think you’d better consider it any more, Father.” 

“I won’t have any threats from my son!”

“Very well.” And Peter strolled off to the nursery.

Peter’s cold and casual threat towards his father is the first indication that there is something seriously wrong with the boy. Peter’s nonchalance as he issues the threat and his false acquiescence as he strolls away is chilling because it shows that the boy knows he has more power than his father does, and that he is disdainfully manipulative. At this point in the story, Peter starts to emerge as the story’s true villain.

“Don’t let them do it!” wailed Peter at the ceiling, as if he was talking to the house, the nursery. “Don’t let Father kill everything.’ He turned to his father. “Oh, I hate you!”

“Insults won’t get you anywhere.”

“I wish you were dead!”

Peter’s tantrum leading to the climax of the story reveals his immaturity as well as his savagery. Without the context of the rest of the story, his threat here might be brushed off as the unserious hyperbole of a sullen child. However, Peter has already shown himself to be an unusual and possibly dangerous boy. This penultimate scene reveals his murderous intent.