Rahul Mithaiwala, portrayed by Shahrukh Khan, is a forty-year-old bachelor living in Mumbai. Orphaned at a young age due to a tragic car accident, he was raised by his loving grandparents, who own a successful sweet-selling business called Y.Y. Mithaiwala. As preparations commence for his grandfather's birth centenary celebration, Rahul’s friends suggest a much-needed vacation in Goa, which he eagerly accepts. However, fate takes a turn when his grandfather passes away unexpectedly while watching a cricket match.
Upon learning about her husband's final wish to have his ashes divided between the Ganges River and Rameswaram, Rahul’s grandmother requests him to fulfill this solemn duty. Initially reluctant and still eager for his Goa trip, Rahul agrees but is faced with an unexpected change of plans when his grandmother insists on seeing him off. This results in him boarding the Chennai Express train with a single ticket to meet his friends at Kalyan Junction for the car ride to Goa.
A series of comedic events unfolds when Rahul forgets to take his grandfather's ashes and rushes back to grab them, only to miss his chance to get off the moving train. It is then that he notices a girl sprinting to catch the train, whom he helps aboard. To his surprise, she starts chatting with him through playful parodies of popular Hindi film songs. This girl, later revealed to be Deepika Padukone as Meenalochni Azhagusundaram, is escaping a forced marriage orchestrated by her powerful father, Durgeshwara Azhagusundaram (played by Satyaraj), to a violent man named Tangaballi.
What starts as a simple trip quickly spirals into an adventure filled with danger as Meena claims that Rahul is her lover, leading him to engage in a duel with Tangaballi. Through clever escapes and twists, Rahul struggles to save Meena from her fate while inadvertently falling in love with her. The duo finds refuge in a remote village where the locals embrace them as a married couple, further complicating their situation as their bond deepens.
With everything at stake, Rahul musters the courage to confront both Tangaballi and Meena’s father, culminating in an intense showdown that tests his limits. Despite being severely injured, he triumphs without resorting to death, showcasing the power of love over brute force. In the end, Meena’s father comes to appreciate the strength of Rahul’s heart, allowing their union.
The film beautifully concludes with Rahul’s heartfelt realization that love transcends boundaries, whether they be regional or linguistic, and emphasizes that with determination and love, a common man can achieve the extraordinary.
