Maddie Kelly, portrayed by Lindsay Lohan, has been harboring a deep affection for Paul Kennedy, a successful author played by Alexander Vlahos, whom she has been editing for the past year. Despite his celebrity status, good looks, and wealth, Maddie keeps her feelings hidden even from her mother, Rosemary, Jane Seymour, who is a school principal in Des Moines, Iowa. Her best friends, Emma (Elizabeth Tan) and Heather (Ayesha Curry), are oblivious to her romantic turmoil, having been friends since their school days.
When Maddie attends Paul's book launch with Emma and Heather, she plans to confess her feelings. However, before she can speak, Paul requests her assistance in writing his next novel, dashing her hopes. To Maddie's dismay, Paul forms a quick bond with Emma, who flirts with him, even claiming to love reading. Paul soon shares his contact information with Emma, further complicating Maddie's emotions.
Three months later, the trio of childhood friends embarks on a flight to Ireland for Paul and Emma’s wedding. Putting her feelings aside, Maddie accepts her role as a bridesmaid alongside Heather. Upon arriving, a luggage mix-up leads Maddie to an argument with a man over their identical bags. Stranded at the lost luggage office and lacking access to an Uber, Maddie's only way to reach the Kennedys is via bus. In an unexpected twist of fate, she encounters the same man again; he turns out to be James Thomas, the photographer she met earlier.
Maddie arrives at the Kennedy estate, an affluent family known for its castle, where she feels increasingly sidelined. The photographer, staying at a local pub and B&B managed by Tim Landers, is in town for a sheep-shearing festival. During a picnic at the lake, Maddie feels like an outsider while Paul and Kory take out rowboats. She stumbles upon a wishing bench, where she whimsically wishes Paul were marrying her. After a sudden gust of wind, Maddie finds herself waking up in a series of surreal circumstances; her suitcase appears with a wedding dress, and Paul steps out of her shower, making her question the authenticity of her dreams.
As who she believes to be her fiancée proposes during a bike ride, Maddie hesitates, deferring to Emma due to her lack of confidence. To her surprise, she is asked to wear an heirloom wedding dress instead of her own. A mysterious fairy, later revealed to be Saint Brigid (Dawn Bradfield), creates further confusion in Maddie's mind. In a moment of serendipity, she collides with James in a Triumph TR convertible, sparking a connection, though he doesn't recall their previous encounters due to the fairy's meddling.
As events unfold, Maddie experiences a restless night with Paul, resulting in an awkward confrontation. She accompanies James on a quest for picturesque wedding photo locations, where he suggests she has been neglecting her own aspirations in favor of Paul's projects. Rosemary's delayed arrival due to a missed flight adds to the chaos. After a storm, Maddie seeks refuge with James at a pub, where they enjoy a night of darts and dancing, deepening their bond.
As the wedding nears, Maddie confronts the unsettling reality of not truly knowing Paul and discovers her true feelings lie with James. Emma, while grappling with her feelings for Paul, puts on a brave face for Maddie's sake. On the wedding day, Maddie's sadness is palpable, yet she confesses her feelings to the priest about her wish for true love. Just before the ceremony, she finds Emma and reassures her of her commitment to mend things.
When Maddie walks down the aisle in casual attire, she makes a jarring declaration that the wedding should not proceed since love is absent. A chaotic confrontation ensues between Paul and James, leading James to leave, causing Maddie to question her choices. In a heart-wrenching moment, they share a kiss before he departs. In a final plea to Saint Brigid, Maddie wishes to reverse her earlier wish, leading time to rewind. Eventually, Paul and Emma marry, and Maddie asserts her stance about co-writing to Paul. In a serendipitous meeting near the pub, she finds James again, and this time he remembers her, igniting the chance for a new beginning together.
