Woh Kaun Thi

Dr. Anand picks up a mysterious woman who calls herself No one on a rainy night. The car's wipers stop working, and she guides him through fog to a cemetery where the gates open on their own, followed by a haunting chorus of 'Naina Barse Rimjhim Rimjhim'.

Anand learns he will inherit a large fortune only if he remains perfectly mentally stable. The family history of mental illness casts a shadow over him and his future wealth. This condition sets up the emotional stakes for the rest of the story.

Anand's girlfriend Seema is killed by a cyanide injection, plunging him into grief and suspicion. The hospital's Dr. Lata and her father, Dr. Singh, emerge as the main suspects, drawing a chilling parallel to the ongoing mystery. The case fuels paranoia about who can be trusted.

On a violent storm night, Anand is called to a dilapidated mansion for an emergency case. The patient is the same enigmatic woman, now dead, and rumors of hauntings surface as policemen describe previous cases of similar sightings. The eerie setting deepens the mystery around her identity.

Anand reads a newspaper clipping reporting that the woman died in a rail accident years earlier. The conflicting signs—from the mansion to the road—fuel questions about whether she is real, a ghost, or a reincarnated memory. The case widens beyond a single haunting.

Anand's arranged marriage to Sandhya is set, but he immediately notices she resembles the woman from the road. He begins to distance himself, unsettled by the uncanny similarities and the lingering dread of the mysterious passenger. The tremors of doubt begin to fracture his trust.

Sandhya paints the same bungalow that figures in Anand's earlier encounter, while he hears her sing fragments of 'Naina Barse'. A stormy car ride triggers a déjà vu, with the windshield wipers failing as she seemingly shows him a path he cannot ignore. He leads her to the old bungalow, where she disappears.

Back home, Anand finds Sandhya waiting on the terrace even as he later spots an unmanned boat on the lake with her singing again. The uncanny signs intensify the sense that something supernatural or preordained is at play. His grip on reality begins to falter.

Seeking peace, Anand travels to Shimla for rest, where a monk on a hilltop recounts a 100-year-old romance: a girl fell to her death, and her spirit remains to haunt her lover who is reborn as Anand. The tale reframes Sandhya and Anand's connection as a reincarnation saga. He sees Sandhya on the hillside and hears the final song fragment.

Returning to the old bungalow, Anand encounters a double of Sandhya and then another version in quick succession. A dramatic confrontation leads to the realization that the staged encounters were part of Sandhya's twin's deception. The mystery deepens as the twin's motives are revealed.

Ramesh, Anand's cousin, reveals his long-running scheme to ruin Anand and claim the inheritance for himself. He claims the police, monk, and servant Madhav were complicit in orchestrating events to drive Anand insane. The revelation ties together the staged hauntings and the fortune at stake.

The superintendent recounts Sandhya's backstory: Sandhya has an identical twin who was separated years ago; the parents' actions created the conditions for the deception. With the truth exposed, Anand and the real Sandhya reunite and the conspirators are arrested. The case closes as love prevails over deceit.