A girl named Mary Morsten comes to Sherlock Holmes, who asks him and the doctor to help solve the annual receipt of one pearl by her parcel and in the search for her father, who disappeared many years ago. Holmes and Watson do not refuse her help and find out that Miss Mary is the heiress of a huge fortune — the treasures of Agra, which are also claimed by the sons of Major Sholto and Jonathan Small — an escaped convict with a wooden prosthesis instead of a leg, whom the elder Morsten and Sholto deceived (while Sholto also deceived Morsten).

Holmes and Dr. Watson help a young lady who is receiving anonymous letters 10 years after her father passed away under shady circumstances. They find themselves in an enigma involving a treasure, murder and a love interest for Watson.

The Adventures of Sherlock Holmes and Dr. Watson is a series of five films produced by Lenfilm for the Soviet Central Television, split into eleven episodes, starring Vasily Livanov as Sherlock Holmes and Vitaly Solomin as Dr. Watson. They were directed by Igor Maslennikov and filmed in Russia (the then Soviet Union) between 1979 and 1986, and the series was one of the most successful in the history of Russian television.