The friendship of three cadets of the Academy of Missile Forces coincided with the events of the Cold War: the Perimeter missile system comes into operation, providing a retaliatory strike against a possible aggressor, an international treaty requires its elimination, but one missile - according to the Western classification "Satan" - left to carry out combat duty in automatic mode. A chain of accidents and a plane crash brought “Satan” out of control: people who knew about its existence passed away, and everyone forgot about the “ambush” missile. The fates of the cadets turned out differently, but most importantly, their friendship ended due to false libel, and their life paths diverged. And only thirty years later, when they found a plane with documentation that had crashed into the taiga, the fates of the general, lieutenant colonel and former captain became intertwined in a tragic knot around the “Satan” preparing to take off...