What did Willie think would happen when he was caught waving a stick at Mister Tom’s dog?

Willie goes out for fresh air: he sees Sammy (Tom's dog). Sammy runs up to Willie in a playful way but since the boy has been told that dogs are dangerous creatures he immediately turns in fright. Willie cries out that he will kill the dog, but then Tom comes and throws away the stick which Willie has picked up to use as a weapon. Willie thought he would be in trouble.