Former Soviet defector-scientist decides to return to his homeland and in exchange for the Government pardon proposes to give up secret "Orbit 12" material. The scientist also has data that will identify a traitor in the Russian special services. Meanwhile, a hired killer arrives to Russia from Europe, and systematically eliminates all those in connection to "Orbit 12". Sergachev forms a special unit to get to the bottom of this old secret, but if he doesn't act fast, the operation will fail, and the one person who possesses answers might falls into the hands of foreign intelligence, or worse yet, the hired killer.