Tchaikovsky worked on the 4-act "Oprichnik" (The Oprichnik) at the estate of his friend Nikolay Kondrat'yev at Nizy and his pupil Vladimir Shilovsky's house at Usovo near Kiev. Tchaikovsky in fact allowed Shilovsky to compose and orchestrate the entr'acte to Act 2 of the opera. Tchakovsky returned to Moscow, moved into his own apartments, undertook work as a part-time music critic, finished another commissioned score and finally completed the opera in 1872.
The libretto was written by Tchaikovsky following Ivan Lazhechnikov's tragedy (1834). Andrey Morozov joins the Tsar's notorious bodyguard, known as the oprichniki, who exist to assert power against the boyars. Andrey is in fact a boyar's son, and enlisted in order to avenge his family's honor against the oppressions of Prince Zhemchuznïy. To complicate this situation, Andrey and the Prince's daughter Natal'ya are in love. Morozova, his widowed mother, disowns and curses him in a powerful ensemble scene. This causes Andrey to request a release from the oprichniki from Tsar Ivan the Terrible. The Tsar's spokesman Vyazminsky assures Andrey that he is released and that the Tsar approves of his marriage to Natal'ya. But the angered Tsar in fact plots to get Andrey to violate his vows just before they expire. Andrey is executed before Morozova's eyes, which also leads to her death.
Tchaikovsky became dissatisfied with the work but the rights were already sold to Bessel so he didn't destroy it. "Oprichnik" isn't performed often, and the first Act is not as developed as the others in terms of characterization, and the melodramatic plot is often described as "Meyerbeer translated into Russian", but the opera has much fine well-orchestrated music to offer - there are several real folksongs and dances employed, touches of Slavonic church music, and rich lyrical cantilenas.