The protagonist, Paul Maddens, portrayed by Martin Freeman, is a teacher at St Bernadette’s with dreams of a successful career in acting, producing, or directing. However, Paul harbors a deep-seated dislike for Christmas due to a heartbreak during the season. The narrative takes a comedic turn when Paul is entrusted with overseeing the school’s nativity play, competing against the local private school, Oakmoor, led by his former drama school rival, Gordon Shakespeare.

Paul’s aversion to Christmas is further exacerbated when he is assigned a new teaching assistant, Mr. Poppy, who, to Paul’s surprise, behaves more like a child than the students themselves. Faced with the challenge of producing a nativity play that can outshine Oakmoor’s, Paul resorts to a desperate lie, claiming that a Hollywood producer, Jennifer, is interested in turning their production into a film.

The lie spirals out of control as Mr. Poppy, in his boundless enthusiasm, spreads the story to the media. Despite the children’s lack of talent compared to their Oakmoor counterparts, Paul, aided by the exuberant Mr. Poppy, endeavors to create an engaging nativity that showcases the unique talents of each child.

As media attention intensifies, Paul attempts to contact Jennifer, even traveling to America in a bid to make his fabricated story a reality. However, reality strikes when he discovers that Jennifer is merely a secretary to a film producer. Disheartened but determined, Paul returns home to face the consequences of his web of lies.

Amidst looming disappointment and the cancellation of the play by the headteacher, Mrs. Bevans, Paul realizes the impact of his actions on the innocent children. Fueled by a newfound determination, he decides that the show must go on, leading to a surprising turn of events.

The nativity play, against all odds, takes place in the historical ruins of Coventry Cathedral, thanks to the Mayor’s generous offer. The children’s performance surpasses expectations, leaving everyone astonished. However, the truth is revealed midway when Gordon exposes Paul’s Hollywood lie.

In a cinematic twist, Mr. Poppy seizes the moment, declaring a helicopter’s arrival as Hollywood descending upon them. The play continues, and to everyone’s amazement, Jennifer and her producer appear, validating Paul’s lie. The play concludes with a heartwarming reunion onstage, bringing together not only the characters but also the audience in celebration of the children’s success.

As the film concludes, Paul and Jennifer, once estranged, are shown decorating Paul’s house together, symbolizing a reunion and the true spirit of Christmas. Nativity! is a delightful blend of comedy, heartwarming moments, and the enduring message that, no matter the challenges, the show must go on. Through the chaos of lies and the pursuit of success, the film underscores the importance of embracing the joy, uniqueness, and magic that Christmas brings.