Gumnaam

On a dark night, Seth Sohanlal is run down by a speeding car and dies instantly. Khanna, watching from a room overlooking the hotel, makes a chain of calls to a doctor, a mysterious young girl, and a lawyer to arrange a medical certificate and a will. Soon after, an unseen intruder in a long coat shoots Khanna in his room, ending his schemes and heightening the danger.

At a nightclub, seven winners are named for a free fortnight abroad: Barrister Rakesh, Dharamdas, Kishan, Kitty Kelly, Dr. Acharya, Madhusudan Sharma, and Asha. The winners are connected to Seth Sohanlal’s murder and the will, though most don’t yet see how closely their fates are tied. The air crackles with a mix of excitement and foreboding as the true stakes emerge.

The seven winners board a chartered plane bound for abroad, but the pilot announces an emergency landing on a remote island. After the group disembarks, the pilot dumps their baggage and flies away, leaving them stranded with no rescue in sight. A mysterious unseen singer begins an eerie song, guiding them toward a vast mansion on the island.

The group follows the singing to a large mansion kept by a comical butler who claims to be expecting them. The butler possesses a diary that logs daily expenses and contains a message accusing the guests of conspiring to kill Seth Sohanlal. A letter addressed to the entire group warns of dire consequences, and the butler seems to know each guest by name.

Kishan is found stabbed to death, a half-smoked cigar resting beside his body, and a letter identifies him as the driver of the car that struck Seth. The group suspects Dharamdas but he pleads innocence, and soon he himself is found strangled, further intensifying the blood-soaked mystery.

Dharamdas is discovered murdered by strangulation, escalating paranoia among the remaining survivors. Anand and Asha try to piece together how Seth Sohanlal’s murder connects to the current island killings, while the letters hint at deeper betrayals within the group.

Dr. Acharya and Madhusudan Sharma are found with Sharma murdered by an axe. A letter beside Sharma claims he was Khanna's co-conspirator, fueling theories of internal betrayal and double-crosses among the castaways. The tension deepens as the group debates who might be orchestrating the killings.

Kitty goes for a walk and is strangled to death by a rope, with Anand's hat left near the body, implying a sinister hand at work. Rakesh tries to pursue the perpetrator but loses the trail in the chaos. Fear grips the remaining castaways as the net tightens around them.

In a night of escalating dread, Rakesh attacks Asha in a fit of rage, attempting to rape her, and collapses dead with two daggers in his back. The lights go out, suggesting the killer is among them, and Asha hides as danger closes in. The mansion trembles with fear as the next move could be deadly.

In a shocking twist, Sharma reveals that he is alive and has been orchestrating the murders as Madanlal, using the butler to carry out his scheme. He admits killing Kishan and Dharamdas, fooling Dr. Acharya into declaring him dead, and eliminating Kitty and Rakesh as part of a long-plotted revenge. The confession explains the tangled web of deceit that brought the group to the island.

Anand reveals he is actually an undercover police inspector tasked with capturing Sharma, the escaped convict known as Madanlal. He and Asha confront Sharma while the butler secretly aids by freeing them, triggering a tense struggle as Sharma tries to flee toward the shore. A contingent of police finally closes in, turning the tide against the killer.

The shifting mystery resolves when the singing ghost is revealed to be the butler's mentally ill sister, Naina. A police airplane lands on the island and Madanlal is arrested, while Anand, Asha, the butler, and his sister prepare to leave. The survivors depart the ill-fated island on the plane, bringing the nightmare to a close.