Feluda and Topshe take a trip to Sikkim, where they learn about the death of a businessman in an accident. Suspecting foul play, they start their Gangtok adventure.

With businessman Selvankar's accidental death, an invaluable idol of the Yamantaka, goes missing too. The Mumbai police also discover a drug connection with Selvankar's perfume company S.S. Chemicals.

Photographer Helmut Ungar, a foreign national, shows Feluda the picture of the missing Yamantaka. Parallelly, police officer Rinchen Gonpo gets suspicious of Feluda and Topshe as their investigation intensifies.

Selvankar's employee Sashadhar Bose entrusts his boss's murder investigation to Feluda. On the other hand, the Mumbai police have a new suspect named Ashwini Kaviraj.

The owner of the original Yamantaka, Nishikanto Sarkar, is attacked following a death threat. Meanwhile, Feluda gets kidnapped by a few masked men.

Feluda visits Dr. Vaidya, an astrologer, who finds out Selvankar's killer by communicating with his spirit. Who is the murderer?

Rinchen is stuck trying to find the Yamantaka and arrests Helmut on suspicion. Feluda and Topshe try out an experiment to solve Selvankar's murder mystery.

Helmut's interrogation takes a surprising turn while Feluda nabs a suspect from Nishikanto's room.

Feluda and Topshe, along with Nishikanto, Helmut, and Sashadhar, reach Lakpa Lodge, only to realise that Dr. Vaidya is missing. However, to their surprise, his walking stick is left behind.

Feluda's interrogation breaks the web of lies while the petal base of the idol gets recovered and handed over to the Sikkim police.