Alexander Krasovytskyi (b. 1967) in the novel «Yesterday» examines historical events through the prism of cognitive science. The author offers an alternative story for understanding real events. If in 2014, after the Maidan, the processes had developed a little differently, if President Yanukovych had not fled to Rostov, would there have been subsequent decisions by the Russian leadership to annex Crimea and start military operations in the Donbass? Would a full-scale Russian-Ukrainian war begin on February 24, 2022? The heroes of the book try to find the roots of everything happening today in the historical past. A scientist-historian predicts the approach of an inevitable catastrophe that will engulf the entire world. He knows the time and the participants in the events, and wants to warn the world about the danger. But will the West believe his prediction? Can the historical experience of the past prevent mistakes in the future?