Main Vaapas Aaunga is a story about Ishar Singh Grewal (Naseeruddin Shah), a 95-year-old resident of Chandigarh, has spent a lifetime alienating his family with his harsh temperament and unyielding nature. One day, he insists on travelling to Sargodha in Pakistan, the place he once called home. His journey is abruptly halted by BSF officials at the border, and the ensuing commotion leaves him battling a stroke. While his family quietly anticipates an end to their long-standing struggles with him, Ishar stubbornly clings to life. His grandson Nirvair (Diljit Dosanjh), settled in the UK and one of the few who genuinely cares for him, returns to Chandigarh upon hearing of his condition. Though Ishar refuses to communicate with others, he gradually opens up to Nirvair. As dementia blurs the boundaries between past and present, Nirvair pieces together fragments of Ishar's memories from pre-Partition Sargodha. There, a young Ishar had fallen deeply in love with Afsana Hasan (Sharvari), and the two dreamed of building a future together. But with Partition drawing near and communal tensions escalating, their love story faces unimaginable challenges. What unfolds next forms the heart of this emotional and poignant tale.