Through the whole war German commanders did not cease their attempts of elimination of Anti-Hitler coalition leaders. The meeting between Stalin, Roosevelt and Churchill planned to be held in Yalta could be a very convenient opportunity in the framework of this goal. In the autumn of 1944 at Kagul railway station during document check senior lieutenant Koshkin was lethally wounded and arrested. Hoping to save his life, he admitted that he was a German agent heading to the Crimea in order to connect with the subversive center. After that the Soviet counter-intelligence started up its own operation. The major of SMERSH, the special section of the Soviet intelligence, was sent to the Crimea to penetrate into the subversive center using documents of Koshkin. Meanwhile the counter-intelligence agency is investigating the mysterious incidents – collision of two trains despite of excellent visibility, disappearing of a group of land surveyors near the forest lake and a pilot suddenly turning his plain to the ground. According to one of the versions Nazis were applying a new weapon that influenced on the human psyche. SMERSH captain Sirota was charged with the special mission. He had to spot the enemy agent and find the documents before anyone else.