1925. Moscow is preparing for an international chess tournament. The leading players are invited, led by the world champion Capablanca. The tournament takes on political significance for the young country: if it goes well, it will be possible to prove abroad that the USSR is not a state of barbarians, but a power with great cultural and intellectual potential. However, a few days before the start, on the outskirts of Moscow, they find the body of an unknown man. During the search, an encrypted note is discovered in his pocket. It says he was a courier for the criminal organization “Black King,” which plans a terrorist attack against the chess stars arriving in Moscow. The GPU perfectly understands that any off-schedule situation—especially an attempt on someone participating in the tournament—will undermine the country’s authority, so they infiltrate a worker into the chess environment: Vadim Arsenyev…