Final of the international chess tournament is held in Alma-Ata, in one of the central museum halls. Armenian and Indian grandmasters are playing the final. The Armenian player wins. At the same time a daring robbery is being planned at the museum. The operation is entrusted to a highly professional expert. The thief, dressed as a waiter, hides the stolen ruby in a chocolate chess knight, while the Armenian chess player, being unaware of anything, takes his second "knight's move": he swallows the ruby of Tamerlane and flies to Armenia...