Twenty-four hours. Two men. One tournament that just became infinitely more compelling.Between the 2018 and 2022 World Cups, Lionel Messi and Kylian Mbappe shared a dressing room at Paris Saint-Germain.On Tuesday night in Kansas City, Lionel Messi scored the first World Cup hat-trick of his career against Algeria, drawing level with Miroslav Klose as the tournament's all-time leading scorer on 16 goals. Juts hours earlier that same evening, Kylian Mbappe struck twice against Senegal to become France's leading scorer in World Cup history and break into the competition's top-five goalscorers list. The 2026 FIFA World Cup has barely begun, yet its two biggest stars are already trading blows in the record books. And if the draw unfolds as many expect, this rivalry could acquire a third and final chapter in July.Where it all beganThe story did not start with records. It started in Kazan in 2018. A 19-year-old Mbappe announced himself to the football world by tearing Argentina apart in a breathtaking Round of 16 performance. He scored twice as France won 4-3, exposing a helpless Argentine defence and sending Messi home yet again without the trophy he craved most. The teenager finished that World Cup with four goals, including one in the final against Croatia, becoming the first teenager since Pele in 1958 to score in a World Cup final. He left Russia with the Best Young Player award and widespread belief that football's throne had found its next heir. Many felt Mbappe had not merely beaten Argentina. He had beaten Messi.But Argentina struck back. Four years later came the response. Not in a group game. Not in a knockout match. In the World Cup final. Lusail 2022 produced one of the greatest matches in World Cup history. Mbappe scored a stunning hat-trick and almost single-handedly dragged France back from the brink twice. Yet even that was not enough.Messi lifted the trophy. Argentina got their revenge. And the rivalry finally had its defining chapter. The youngster had landed the first blow in 2018. The veteran answered in the most important match imaginable in 2022.Teammates in betweenBetween those two World Cups, Messi and Mbappe shared a dressing room at Paris Saint-Germain. There were questions about whether the scars of the final would create tension between them. They never did.They were not close friends, but they respected each other. Mbappe consistently spoke about his admiration for Messi, while Messi acknowledged the Frenchman's extraordinary talent.Eventually, they moved on. Messi headed to Inter Miami. Mbappe fulfilled his dream move to Real Madrid. Two very different destinations, two very clear statements of intent. But four years since that final in Qatar, the paths have converged again.The last dance and the coronation bidMessi's performance against Algeria felt symbolic. At 37, and playing what is almost certainly his final World Cup, he arrived carrying a minor hamstring concern. Yet he still produced a hat-trick in his 200th appearance for Argentina. The first was a thunderous long-range drive that gave Algeria's goalkeeper no chance. The second was a composed tap-in. The third was a curled finish into the bottom corner.This was Messi's farewell tour. Those in Kansas City knew it. His teammates knew it. And Messi too. And yet there was nothing valedictory about his performance. No sentiment, no ceremony. Just three goals, a standing ovation when he was substituted, and Argentina took their first steps towards defending a title no team has managed since Brazil in 1962.Mbappe, meanwhile, is 27 and playing with the urgency of a man chasing unfinished business. He won the World Cup at 19 and came within touching distance of retaining it at 23. Now, he is hunting it again.His brace against Senegal was a reminder that the disappointment of Lusail has not faded. If anything, it has fuelled him.There is another layer to all of this. Messi is setting the benchmark; Mbappe is chasing it. Whatever tally Messi finishes with at this World Cup, Mbappe will almost certainly have two more opportunities, in 2030 and 2034, to surpass it.Yet the most tantalising possibility of this tournament lies elsewhere. Argentina and France have been placed on opposite sides of the bracket, meaning they can only meet in the final. If both navigate their way through the competition, football gets its trilogy. Kazan in 2018. Lusail in 2022. And perhaps MetLife Stadium in New Jersey in 2026. It would be Messi's final World Cup and perhaps his last shot at adding one more glorious chapter to an already unparalleled career. For Mbappe, it would be a chance to complete his rise from football's brightest young talent to its undisputed leading man.Opta's supercomputer rates Argentina, France and Spain among the leading contenders for the title. If those predictions hold true, football may yet receive the ending it secretly wants. And if it does, the final chapter of Messi versus Mbappe will be written one goal at a time.