Horrid Henry, Theo Stevenson, is once again dodging his homework, and his scheme to skip the blame backfires in a playful yet sharp schoolroom moment. His friend Brainy Brian, Reuben Lee, helps by forging a note from Henry’s mother claiming that his cat ate the homework. But Miss Battle-Axe, Anjelica Huston, sees right through the ruse—the word “homework” is spelled correctly, a small detail that betrays Henry’s usual shortcuts. What follows lands Henry in detention, where his crew of friends joins him, and they begin rehearsals for a school talent contest. Their bubble of creativity is interrupted by the formidable Miss Oddbod, Rebecca Front, who oversees the headmistress’s office, and two sharp-eyed school inspectors who are already sniffing out trouble.
Meanwhile, the school’s future teeters on the edge of collapse as Vic Van Wrinkle, Richard E. Grant, the crooked headmaster of the elite Brick House School, uses his influence to persuade the inspectors to shut Ashton Primary down. His plan is to profit from an influx of new students drawn by the closing of a beloved local school. Under his pressure, Miss Battle-Axe and her colleague Miss Lovely, Parminder Nagra, are dismissed for failing to keep discipline in line. The inspectors even bar Henry’s band, the Zero Zombies, from entering the school talent contest, worsening the already precarious situation at Ashton Primary.
Into this maelstrom steps Great Aunt Greta, Prunella Scales, who proposes to fund Henry’s transition to an all-girls private academy (mistakenly assuming Henry is a girl) while sending his little brother Perfect Peter, Ross Marron, to Brick House. Miss Lovely, determined to resist Van Wrinkle’s scheme, applies for a job at Brick House and begins to spy on him. She’s captured, yet manages to pass crucial notes about Van Wrinkle’s plan to Peter, who becomes a secret conduit of information. With Ashton Primary on the brink of closure, Henry escapes from his new school with help from Moody Margaret, Scarlett Stitt, who has also been transferred there. Together, Henry and his band push forward to prove their talent can change their world.
The talent contest becomes a lifeline for Ashton Primary, and the Zero Zombies throw themselves into the performance with renewed energy. They win the contest, but Miss Oddbod bluntly informs Henry that fame alone won’t save the school, sealing a difficult truth: Ashton Primary will still close unless something else changes. The wheels keep turning as Henry receives an invitation to participate in the game show 2 Cool 4 School, a televised push toward one last chance at salvage. Margaret suggests using the cash prize as leverage to influence the inspectors, a plan that puts a glint of hope back into the equation.
In the tense final round of 2 Cool 4 School, Henry confronts Miss Battle-Axe again and faces the ultimate spelling challenge: “homework.” He draws on the memory of Miss Battle-Axe’s cautions and uses the mnemonic phrase “Oh, Henry” to guide his fingers and finally spell the word correctly, securing the competition’s win. The triumph is bittersweet, because it won’t by itself save Ashton Primary—yet the victories ripple outward in unexpected ways.
Meanwhile, Peter and his allies attempt a dramatic rescue of Miss Lovely, but they are captured. Miss Lovely uses the moment to trick Van Wrinkle into revealing his own plan while Peter keeps a mobile phone on a call with Miss Oddbod, who contacts the police. Van Wrinkle tries to escape, but Peter ties his shoelaces together, sending him sprawling. The corrupt headmaster and the school inspectors are arrested, and the authorities close in on the scheme.
Back at Henry’s house, the prize money becomes a shared gift rather than a personal windfall. Henry offers the cash to Miss Oddbod, who declines, explaining that the school’s future is already secured by the capture of Van Wrinkle and the arrest of the inspectors. Ultimately, the resources are put toward throwing a grand party at Henry’s home, a celebration that marks a turning point not just for Ashton Primary but for Henry’s own sense of responsibility. The film closes with a sense of community restored, a reminder that even mischievous schemes can teach big lessons when they’re driven by wit, courage, and a willingness to do the right thing.
