A young man named Kanan (Suraj Sharma) travels back to India from Canada to marry his long-time girlfriend Anu (Mehreen Pirzada). However, he discovers that due to being a Manglik (born under an unlucky star), he must first marry a tree before uniting with her. Reluctantly, Kanan follows through with this unusual tradition, only to find himself haunted by the spirit of Shashi (Anushka Sharma), the woman who lived in that tree and now claims to be his 'wife'.
The film unfolds Shashi's poignant story through her flashbacks. In a time long past, Shashi is a vibrant young woman engrossed in the poems of a local poet known as Phillauri. The village’s heartthrob, Roop Lal 'Phillauri' (Diljit Dosanjh), notices her unique absence at his performances. When he confronts her and admits that he is the one writing the poetry, Shashi challenges him. She tells him to use his gift for greater causes rather than frivolous matters, especially during the burgeoning struggle for independence. This moment transforms Roop Lal, igniting a newfound purpose in him to share the essence of Phillauri's poetry, which he ultimately realizes was never his to begin with.
As fate weaves their lives together, one evening while singing a poem, Roop Lal encounters Shashi, who reveals herself as the true poet behind the words he has celebrated. Their love flourishes as she inspires him to take her words to a larger audience. But their path is not without obstacles. Shashi's elder brother, a respected village doctor, discovers their affair and confronts Roop Lal. Acknowledging his past failures as an alcohol-dependent drifter, Roop Lal vows to prove his worth and expresses his intent to marry Shashi after recording her songs in Amritsar.
Time passes, and as Roop Lal secures a recording, he sends the earnings home with a heartfelt letter proclaiming his love and intent to marry Shashi on Baisakhi. However, on the day of the wedding, Shashi learns of her pregnancy but keeps it to herself, anxiously awaiting Roop Lal’s arrival. As hours pass with no sign of him, despair envelopes her, leading to a heart-wrenching decision as she succumbs to the depths of sadness and betrayal.
Meanwhile, Kanan's modern-day struggles are compounded by his increasingly fraught relationship with Anu, who feels distanced from him amidst his ghostly encounters with Shashi. In an unexpected turn, Shashi reveals her presence to Anu, who slowly begins to understand the significance of Shashi’s unfinished story. When her grandmother plays a cherished record from Roop Lal, its date unwittingly connects to the tragic Jallianwala Bagh massacre, which strikes Kanan with clarity.
In the film’s emotionally impactful conclusion, Kanan, accompanied by Anu and the spirit of Shashi, visits the site of the massacre. Shashi's spirit finds solace as it reunites with Roop Lal, who perished on the very day he was meant to marry her. Before their celestial ascent, Shashi imparts heartfelt words to Kanan and Anu, imploring them to cherish their love eternally—a promise they embrace as they embark on their own romantic journey.
