Summer 1948. 14-year-old Alan Duckworth dreams of cricket (England vs Australia) and kissing classmate Ann. On the way to school he imagines he is bowling to Don Bradman. He accidentally squashes a spider, and many baby spiders crawl out.

Alan arrives late for school, but stops to talk with Tommy the caretaker. When Alan reaches his classroom, his teacher, Estelle Land, tells him he will see the headmaster for persistent tardiness. Alan, along with his friend Shaz, is sent out of the classroom for misbehaving.

In gym class, Shaz tells Abbo, another of Alan's friends, that he has put his hand down a girl's blouse. The gym instructor sends Alan to the headmaster, who canes him.

Eunice conducts the girls in a vote on the best looking boy in class 4B. Ann votes for Geoffrey Whittaker. Alan talks to Tommy about his heroic experiences fighting World War II.

Eunice announces the dishiest boy in class 4B is Geoffrey. Fourth place is Shaz, while Abbo comes last. Eunice apologises to Alan, nicknamed 'Quack Quack,' since they forgot to include him.

The headmaster asks Estelle to take drama class. He refers to their intimate relationship during the war, but Estelle reminds him those days are over. After initial resistance, Estelle agrees to direct the school play.

Alan follows Ann home, but pretends to be tying his shoes when she sees him. He walks home in frustration.

Estelle and Tommy meet at night. They are worried that Estelle is pregnant, because her period is late. Tommy tells Estelle that marriage is impossible, as she would be sacked, and they dislike each other.

Estelle casts Geoffrey and Ann in the play. She gives Alan the role of Antoine the Philanderer to "wake him up." Alan is pleased when he realises he will play opposite Ann.

Shaz reads the play by the canal, and realises that Alan's role will require him to kiss Ann. Alan pretends to be annoyed, but is secretly delighted.

During rehearsal, Estelle's period arrives. She excuses herself. Geoffrey and Ann flirt before saying goodbye. Alan pretends he has an errand in Palmerston Way, so that he can walk Ann home. Ann tells Alan she detests the made-up slang words that he and his friends use. She thinks he is a drip.

Estelle and Tommy celebrate that Estelle is not pregnant. They arrange to meet on Sunday night.

Alan hopes to rehearse his kissing scene, but Estelle simply reads the stage directions, ending rehearsal for the day. In a following rehearsal, Alan dries his lips in preparation for the kiss, but Geoffrey asks to leave early, halting proceedings. Alan will not have a chance to practice before the actual performance.

Geoffrey arranges to meet Ann at the Odeon on Saturday. Alan walks Ann home, pretending to have another errand. Ann informs Alan that "real men don't mess about dreaming."

While the play is being performed, police arrive, arresting Tommy outside. Meanwhile, Alan falters while trying to kiss Ann in the final moments of the play. He shakes her hand instead. Estelle is furious.

The police tell Estelle of Tommy's arrest for desertion during the war. He will face a court martial. Tommy has left a message for Alan, asking the boy not to think badly of him.

Ann asks why Alan could not kiss her. She ignores Geoffrey as he says goodbye, instead asking Alan to walk her home. Alan explains that he is confused. He tells her about the spider, which Ann realises must have been pregnant. Alan tells Ann that he has wanted to kiss her ever since 3B. She thanks him.

Alan explains his inability to kiss Ann through the metaphor of a cricket player facing a bowler with thousands watching. They play their stroke, but Alan felt unable to. When Ann offers him a kiss, he refuses, saying it is too late. Ann feels he is being cruel, but when Alan says goodbye, she gives him a kiss for good luck.

As Alan returns home, he imagines a commentator celebrating his contribution to a record-breaking victory for England's cricket team, "Quack Quack Duckworth, who went to the wicket a boy and came back a man."