Private Detective, or Operation Cooperation or (Russian: Частный детектив, или Операция «Кооперация», romanized: Chastnyy detektiv, ili operatsiya "Kooperatsiya") is a 1990 Soviet comedy film directed by Leonid Gaidai.

At the same time, Lena Pukhova, a young journalist, is searching for stories for her newspaper and goes undercover, disguising herself as an alcoholic prostitute.

The agency gets its first real client, Anna Petrovna, who asks Dmitry to track down her kidnapped husband Ivan Ivanovich, Chairman of the "Joy Cooperative", a leading business.

With the help of his father, Dmitry decides to stage an ambush but then falls into the clutches of the villains, along with Lena, who happens to be Ivan Ivanovich's daughter.

Realizing that his plan has been foiled, Victor decides to kill the gang's prisoners: Dmitry, Lena, and her father.