Penrod Schofield is a twelve-year-old boy whose vivid imagination and deep suspicion of the adult world constantly land him in extraordinary trouble. As the story opens, Penrod faces a genuine crisis: he has been drafted to play the Child Sir Lancelot in a charitable pageant organized by his mother's well-meaning friend. To escape the humiliation and his hatred for the poetic sentimentality of the role, Penrod retreats to the family stable, where he pens sensational stories of the wild west under the grand persona of Harold Ramorez, finding solace in his own dramatic creations and the loyal, if bewildered, companionship of his dog, Duke.
Unfortunately, escape proves impossible. Penrod is relentlessly dragged into the preparations, subjected to costumes cobbled together from old silk dresses, discarded undergarments, and golf capes. When he finally sees his reflection, his revolt is volcanic, setting the stage for public disaster during the pageant itself. Driven to desperation by the anticipated mockery of his peers, Penrod takes matters into his own hands with results that shock the gathered townspeople and turn a solemn theatrical spectacle into a cultured riot.
From the catastrophic aftermath of the pageant, Penrod drifts into other grand enterprises, including a short-lived partnership in a commercial rag trade and the staging of a neighbourhood 'Big Show' featuring his friends, a tattooed wild boy, and an eccentric cousin. Yet, throughout every escapade, Penrod's greatest battles are fought against the incomprehensible expectations of grown-ups and the baffling codes of polite society, particularly embodied by girls like the golden-curled Marjorie Jones.
As the narrative progresses, Penrod contends with the trials of dancing school, the bewildering discovery of romance, and the chaotic results of concocting a spurious 'smallpox medicine' in an old spice bottle. His adventures are marked by intense interior daydreams where he navigates the skies or battles dastardly outlaws, juxtaposed sharply against the mundane scoldings of teachers and parents who view him simply as the worst boy in town.
Through a series of escalating catastrophes—culminating in the Great Tar Fight and a disastrous birthday party—Penrod slowly stumbles through the final borders of his early childhood. The story balances sharp social satire with a deeply sympathetic portrait of a boy's inner life, capturing the poignant reality that a year in a child's world is an epic of emotional survival and growth.
