Sergeant John Mackenzie is flying to Russia from the United States under the professional exchange program. The American not only becomes the partner of investigator Vasilisa Vikhreva, but also temporarily settles in her apartment. It's hard for John and Vasilisa to work together — the difference in characters and mentalities affects. But the successful results of joint investigations convince the leadership to create a special department around them to combat crimes committed by foreigners and against foreigners in Russia. Unraveling one case after another, the partners find themselves embroiled in an international espionage game around a major scientific discovery.