Princess Stacy Wyndham of Belgravia and Queen Margaret Delacourt of Montenaro are gearing up for the grand international Christmas festival set to take place in Montenaro, where the event's highlight is none other than the "Star of Peace," a revered relic graciously loaned by the Vatican for the occasion. However, shortly after the Star’s arrival, the palace falls victim to a brazen heist as thieves break in and make off with this priceless treasure.
In a twist of fate, Stacy and Margaret find themselves turning to the rather unconventional Lady Fiona Pembroke, portrayed by Vanessa Hudgens, who is currently serving time on probation and working as a custodian at a local orphanage. In a surprising turn, Fiona agrees to assist in recovering the Star, but not without an exchange: she seeks Margaret's help to speak favorably on her behalf when her case is brought before the disciplinary board post-Christmas.
To tackle this formidable challenge, Fiona turns to her ex-boyfriend, Peter Maxwell, a character played by Remy Hii, who once held the prestigious position of an Interpol investigator but now operates his own private security firm. Peter’s investigation leads him directly to the culprit: Hunter Cunard, the billionaire art thief, portrayed by Will Kemp, known for his obsessive quest to hoard the world’s most invaluable artworks into his private collection.
Using her charm and wit, Fiona manages to secure an invitation to Hunter's opulent Christmas party. To ensure success, Peter enlists the help of Fiona’s quirky assistants, Mindy and Reggie, rehearsing various escape maneuvers to infiltrate Hunter's heavily guarded estate during the festivities while Fiona keeps Hunter occupied at the party.
However, an unforeseen twist occurs when Reggie injures himself during the rigorous training phase. Faced with this setback, Margaret steps in to impersonate Fiona at the gala. Meanwhile, Peter and Fiona take over Reggie’s role with the sole aim of retrieving the Star from Hunter’s security vault. As this daring plan unfolds, Fiona finds herself reflecting on her long-standing feelings for Peter, which trace all the way back to their childhood.
As the plan goes underway, everything initially proceeds as outlined until Peter accidentally triggers a pressure plate alarm while attempting to secure the Star. In a flurry of panic, Reggie and Mindy hasten to disable the misleading security footage that Peter had cleverly set up, which subsequently alerts Hunter to the theft. Leaving Fiona with the Star in a bag, Peter remains behind to deflect Hunter's henchmen, while Margaret makes her escape with the aid of a coat-check attendant.
Simultaneously, Stacy gets news from the orphanage's head that the hearing regarding Fiona's case has been rescheduled to coincide with the heist. Taking matters into her own hands, she decides to dress up as Fiona and appear before the committee, with Prince Edward, played by Sam Palladio, attesting as a character witness. As Stacy convincingly portrays a remorseful Fiona, the board is swayed into granting a commutation of her sentence.
As everyone regroups at the palace after the chaotic escapades, Fiona soon realizes that the bag she carries is nothing but a deceptive decoy. Upset and feeling betrayed, both Margaret and Stacy contemplate revealing the unsettling truth to the Vatican while Fiona and her friends, Mindy and Reggie, consider making a hasty exit from the kingdom despite Margaret's invitation to linger for Christmas festivities.
However, pivotal moments unfold when Peter seeks out Fiona to explain his motivation for taking the Star—it was to draw her attention. He implores her to connect with her estranged mother, Bianca, showcased by Amanda Donohoe, who has come to Montenaro seeking reconciliation with her daughter. Fiona, at first stubborn and unwilling to forgive, has an epiphany—by refusing her mother, she’d replicate the mistakes of her own past. She embraces Bianca, choosing the path of forgiveness, and together they return the Star just in time.
As the festival culminates with the lighting of the majestic Christmas tree, Margaret candidly reveals to Kevin, portrayed by Nick Sagar, that she has provided the police with crucial evidence pertaining to Hunter's transgressions. Meanwhile, even as Fiona rejoices in her reintegration into her cousin's family, a pang of sadness strikes as she considers sharing this holiday alone. Just then, Peter reappears, despite their previous conflict, and they share a tender kiss as the Star of Peace illuminates the night, signaling a beautiful start to the new year.
