Georgy Topilsky, an attaché of the Russian embassy in the United Kingdom, receives an anonymous letter stating that its author has information about where secret materials—handed to him by the Soviet разведчик Herman Kroyus—are kept. These materials relate to the “Bereg” project carried out in South Africa in the early 1990s of the last century. Handwriting analysis showed that the letter was written by a not-very-young man, most likely an Arabic-language speaker. No fingerprints were found on the paper. The information received was undoubtedly important and interesting, but there was one small inconsistency. Up to 1991, there was an apartheid regime in South Africa, and at that time there were no diplomatic contacts between the USSR and South Africa. How could a Soviet intelligence officer end up there—and moreover, pass along any secret information from there? What kind of strange “Bereg” operation was this? Could it be the project in which the so-called killer doctor Bason led a secret laboratory for developing chemical and biological weapons, to fight the regime’s enemies? It seems that finding answers to all these questions is possible only by meeting the author of the letter in person. Therefore, senior inspector of the FSB counterintelligence department’s English section Oleg Konstantinovich Yermilov has no choice but to go on another foreign business trip—this time to the capital of the United Kingdom, London.