After the death of his wife and the murder of his son, Professor Gregor Antonov, a European chess master and key scientist in an important Soviet defense project, has become increasingly disillusioned with his work in the Cold War arms race. Disheartened, he has thoughts of defecting to the west, where he will live a quiet life together with his 15-year-old daughter Sasha, his only remaining family member. Soviet officials are however well aware of Antonov's hopes, and thus the security around him is rigorous. Jim Phelps and his team of agents are assigned to the mission of smuggling Antonov and his daughter out of the Soviet Union and to safety in the west. The perfect opportunity to do this appears to be during a chess tournament in Czechoslovakia, where the chess master Antonov is due to participate.
—Anonymous