Time travel

The movie begins in 1984 as Flight JL50 takes off from Kolkata. Midway through the flight, the plane encounters severe turbulence and bad weather. Communication is suddenly lost, and the plane disappears without a trace. No clues are found regarding its disappearance. The story then jumps 35 years ahead to 2019, where a remote village named Lava in West Bengal becomes the focal point. A group of children playing football witnesses a rare sight—a large plane flying over their hilly area. They rush towards the crash site and discover the wreckage in the nearby hills.

The scene shifts to Kolkata, where the protagonist, Shantanu, watches a news report about the missing Flight AO26, which had several high-profile individuals on board. It is suspected to be a hijacking case. Shantanu, a senior officer at the Central Bureau of Investigation (CBI), heads to the crash site with his colleague, Garanga, to investigate. They discover that only two people survived the crash—the pilot and a passenger. Strangely, a passenger's corpse is found in the cockpit, indicating that the plane was hijacked before it crashed.

While preparing to visit the crash site, the CBI officers receive a crucial revelation from a soldier—they have been investigating the wrong crash. The crashed plane is not Flight AO26; it is, in fact, Flight JL50 that disappeared 35 years ago. The movie then shifts back to 1984 and introduces Bihu, an aspiring pilot from Kolkata. Bihu, who seems to have everything in life, becomes increasingly upset in the past few months. In the present day, Bihu is fighting for her life in the hospital, revealed to be the pilot of the crashed Flight JL50.

Meanwhile, Shantanu and Garanga visit a remote village and interrogate Dr. Subroto Das, a physics professor. Shantanu reveals that Flight JL50 disappeared in 1984, and one of the seats belonged to Dr. Das. Though momentarily stunned, Dr. Das claims not to remember the past due to his old age. Later, Dr. Das burns some documents and pictures, indicating his knowledge about the plane crash.

A news report reveals that a terrorist organization called the ABA has claimed responsibility for hijacking Flight AO26. They demand the release of their leader, Partho Majumder, in exchange for the passengers' safety. As the officials plan to surrender to their demands, Bihu regains consciousness, and Shantanu interrogates her. She narrates the events leading to the crash, including the hijacking and the severe weather that caused the plane to crash.

Santanu questions the credibility of Bihu's story, stating they are in 2019. Bihu takes him back to her old house, where they meet a couple who provide insights into Bihu's past. They reveal that Bihu's career as a pilot declined when she got involved with a man who made her pregnant before marriage. Tragically, her child was stillborn, which pushed her to the breaking point. A photo album confirms her appearance in 1984, despite being in the hospital in 2019.

Santanu listens to the black box recording of Flight JL50, confirming Bihu's account of the hijacking. The last recorded activity on the black box was on August 23, 1984. The indestructible nature of the black box leads them to believe that the plane somehow traveled through time. The second survivor, Mitra, regains consciousness and attempts to finish off Bihu. However, Santanu intervenes, leading to Mitra's escape.

Santanu conducts research on Mitra and discovers that he was a genius and a professor involved with left-wing activism and terrorist organizations 35 years ago. He also learns that Mitra had extensively researched time travel and discovered wormholes in the Earth's atmosphere. Mitra's plan was to hijack a plane and use the wormholes to travel to another timeline. He formed an alliance with Partho Majumder, the terrorist leader responsible for the hijacking in the present.

Santanu confronts Dr. Das, who admits to knowing Mitra's plan. Dr. Das wanted to use Santanu to travel back in time and steal the papers related to the project. Santanu refuses to believe the story initially but eventually realizes the gravity of the situation. Dr. Das suggests that they enter the wormhole to 1984 and prevent the hijacking of Flight JL50, which would erase the criminals and their organizations from existence.

The trio, including Bihu, embark on the mission. However, they are unexpectedly transported back to the present due to a change in the past. In this alternate reality, Flight AO26 and JL50 were never hijacked. Santanu, now on the plane with his wife, runs into Garanga but doesn't recognize him. The movie ends with Santanu celebrating his birthday at the orphanage, where he is reunited with his mother, Bihu. The alternate timeline brought them together, and they now live happily, grateful for their new lives.

This is just a condensed summary of the movie, if you want a more elaborate explanation, drop it in the comment section.