Just like any good story, this one starts with Rob Peck (our narrator) playing hooky from school.
Rob lives on a farm, so instead of going to the mall like most kids when they play hooky, he wanders around a hill. Um, fun?
Along his walk, he comes across a neighbor's cow partway through giving birth to a calf. Yikes. Rob helps the cow birth the calf, but in the process, he gets pretty banged up. He ends up being carried home by the neighbor, Mr. Tanner. He arrives home unconscious, with no pants (long story there) and a great bloody gash on his arm. Karma for skipping school, anyone?
Rob's Mama and Papa, who stand out for they religiousness and poverty, patch their kiddo up and put him to bed. He spends a week or so recovering, and gets better just in time to be given a sweet little piglet as a thank you present from Mr. Tanner. He was hoping for a Wii, but hey, you take what you can get. Creatively, he names his new pig Pinky.
As pinky grows from piglet to, um, pig, she and Rob have lots of adventures. To name a few: they hang out together watching the clouds drift by; they have a silly run-in with a frog; and they watch a hawk kill a rabbit. Did we mention this is all going down in the wayback days? On a farm? Yeah.
Over the summer, Robs gets himself into all sorts of interesting episodes with the Peck family's neighbors. But nothing tops the time when he gets to take Pinky to the fair in nearby Rutland with Mr. Tanner. While he's there, Rob is overwhelmed by all the sights and the people, and he finishes his day by vomiting out his lunch onto one of the judge's shoes. Oops. Pinky wins a blue ribbon, though, and Rob returns from the fair a happy boy. Hey, it's all about priorities.
Soon after coming home, Rob learns from Papa that Pinky might not be able to have babies. This is a pretty big deal; poor as the Peck family is, they had been counting on Pinky's piglets to bring in some extra money. Not depressing enough for you? How about this? Papa himself may actually be dying. When it rains, it pours, huh? Mr. Tanner brings his boar, Samson, over to the Peck farm in an attempt to make some little piggies with Pinky, but nothing doing.
As winter comes on and the Peck family slips closer and closer to the edge, Papa (who butchers pigs for a living, in addition to keeping the farm) decides that they have to kill Pinky and turn her into food to get the family through. He and Rob are both heartbroken by the whole thing—Rob even sees Papa cry for the first time—but they know what they have to do.
The family makes it through the long winter, but Papa dies the next spring. Rob, who's done some major growing up over the course of the book, steps up as man of the house and makes all the arrangements for the funeral. Although he's only 13 years old, he's a man now, and he'll step into his father's shoes in taking care of his family.