Pradosh Mitter, also known by his friends as Feluda, is a private detective. Along with his cousin, Tapesh, he takes a summer holiday to Gangtok, the capital of Sikkim. When their plane lands at Bagdogra Airport after a flight from Dum Dum, they decide to eat at the airport restaurant before leaving. In the restaurant, they meet a man named Sasadhar Bose who asks them if he can come to Gangtok in their jeep. Mr. Bose is on a business trip to look for aromatic plants. They hear people talking about an accident, and when they inquire they find out that a man had been killed in a freak accident by a falling boulder on the road. Mr. Bose discovers that this man was his business partner, Mr. Shivkumar Shelvankar. At the hotel they are staying at, Feluda and Tapesh, also known as Topshe, meet a man named Nishikanto Sarkar who sold a Tibetan statue Yamantaka to the dead man, Mr. Shelvankar. Later, Feluda and Topshe meet a German photographer who claims to be called Helmut Ungar but is actually the son of Mr. Shelvankar, Virendra. He is suspicious of the fact that the statue was not found with Mr. Shelvankar’s body. He tells them about a man named Dr. Vaidya, who claims to be able to act as a medium, read palms and predict the future. They visit the Tibetan Institute to investigate about the statue, and their taxi driver tells them about the accident. They discover that Mr. Bose is leaving for Bombay, so they ask him to investigate when he reaches. Mr. Sarkar invites them to a Lama dance in Rumtek Monastery. That night, somebody throws a note into Mr. Sarkar's room, with the Tibetan word for death written on it. Feluda and Topshe then go to the site of Mr. Shlevankar's accident to investigate, and they discover that his death was not an accident. At the Lama dance, they find that Mr. Sarkar has been pushed off a hill and is barely hanging on to a bush. They help him to recover and head back to the hotel. They then meet Dr. Vaidya, and Feluda conducts an experiment. Virendra, or Helmut, shows them pictures that prove that Mr. Shelvankar’s death was not an accident. Using his powers of deduction, Feluda names Dr. Vaidya his prime suspect and he goes to Pemiangchi with Topshe, Helmut and Mr. Sarkar to find him. On the way, Sasadhar Bose, who had returned from Bombay, also joins them. The five then head towards Pemiangchi to catch Dr. Vaidya. On reaching there, Feluda learns that Dr. Vaidya had come to Pemiangchi, but has fled a day before Feluda reached. Surprisingly, he had left behind his walking stick, which he always used. Sasadhar Bose wanted to lunch before they again start on their journey to find Dr. Vaidya, but Feluda cuts him short with the firmness of his voice, "Khaowa pore hobe.." (The lunch can wait). Feluda then deduces, in front of the rest of the group, that Sasadhar Bose is actually Dr. Vaidya, who murdered Mr. Shelvankar to become the sole owner of their business. He also stole the Tibetan statue from the coat pocket of the dead Shelvankar. Bose tries to flee in the nearby jungles, and Feluda and Helmut find him attacked by leeches and capture him. He is later arrested by the police.