The Secret Agent's Blunder (Russian: Ошибка резидента, romanized: Oshibka rezidenta), also translated as Resident's Mistake, is a 1968 (or 1966?)

[2][3] Mikhail Tulyev, the son of a former spy and Russian Empire count, is sent by West German intelligence to collect Soviet nuclear secrets.

He travels in Russia under the name Mikhail Zarokov, taken from a POW he had met in the Great Patriotic War, with the cover of looking for his supposedly lost sister.

Tuylev stays with Dembovich (Oleg Zhakov), a bitter former German agent and works as a taxi driver, striking up a romantic relationship with the company's dispatcher, Maria Nikolayevna (Eleonora Shashkova).

After setting fire to Dembovitch's house, Tuylev, pursued by the KGB, switches cars, escapes, and manages to leave behind a considerable amount of money for Maria, who is pregnant with his child.