“Ek Thaa Raja, Ek Thi Raani… Dono Mar Gaye, Khatam Kahaani”
The film opens with Shiv moving from India to Budapest for a job as a banker, along with his friend Radha. Shiv is shown to have been a fun-loving womanizer back home and continues this behavior in Budapest. Saira is haunted by mysterious nightmares of drowning to death. She lives by herself in Budapest and works as a chocolatier. Shiv happens upon Saira's shop while on a date with a woman but finds himself deeply attracted to Saira. Though she initially rejects his advances, she eventually succumbs and sleeps with Shiv, revealing the next day that she actually has a boyfriend and what happened with Shiv was a mistake. Unwilling to let go of their connection, Shiv interrupts their date and shows Saira that she would rather be with him than with her boyfriend. Saira's boyfriend angrily breaks up with her, and Shiv and Saira start spending time together, growing close. One night, they go to a club with Radha, where they happen upon an eccentric psychic who knows about Saira's nightmares and tells her that the events of her previous life will repeat themselves, and only she can fix them. Saira tearfully reveals to Shiv that she has a fear of water because her parents drowned after a car accident when she was two years old.
While trying to test their love a final time, Shiv and Saira make a pact. Shiv flirts with multiple women, but Saira finds herself strongly drawn to a young businessman Zakir "Zak" Merchant. Shiv reveals he has to leave for a business trip for a week and he and Saira decide to see how they feel after a week's separation. If they still feel strongly about each other, they will start considering marriage. During Shiv's absence, Saira gets to know Zakir better and confides in him about her nightmares. During one of their dinners, Zakir drugs Saira and kidnaps her.
Saira wakes up and finds herself trapped in Zakir's isolated mansion on an island off the coast of Croatia. She demands that he let her go, but he refuses, saying that he spent his whole life looking for her. He explains that they were madly in love in a previous life, but were separated. He refuses to let this happen again. When she does not believe him, he shows her a collection of uncannily accurate paintings he made of her at various ages and says she will find the explanation for her nightmares. Thinking he is crazy, she attempts to escape but ends up falling into the ocean, which triggers her memories of her previous life.
Hundreds of years ago, Saira was the warrior princess Saiba. She was in love with Kaabir (Jim Sarbh), a fellow warrior from her tribe. Their kingdom was threatened by the Muraakis, led by a wise old ruler. Kaabir is severely wounded by the fierce Muraaki warrior Jilaan (Sushant Singh Rajput), who gives Kaabir an ultimatum to surrender. Saiba challenges Jilaan, and they find themselves attracted to each other. Saiba accepts defeat, surrendering the kingdom to the Muraakis and herself to Jilaan. Kaabir attempts to take Saiba back, but she reveals that she and Jilaan have fallen in love. On their wedding night, a comet falls and the Muraaki ruler realizes that this will be a fateful night. Kaabir ambushes Jilaan and Saiba, and murders Jilaan by wounding him and having him thrown in the ocean. Saiba jumps into the ocean to save him, but to no avail. When she herself dies in the water, Kaabir slits his own throat, killing himself. The Muraaki ruler forebodes that these events will repeat.
However, this time, when Shiv shows up to get Saira back, Saira, convinced that Shiv loves her, decides to fight back against Zakir. When their previous lives' events repeat - Zakir throwing Shiv into the ocean - Shiv drags Zakir down with him and Zakir dies. Saira jumps into the water and is able to save Shiv this time.
The film ends with Shiv humorously telling their children to not believe Saira if she tells them any far-fetched stories about reincarnation, implying that he is still oblivious to the fact that they had a past life.