Deeply undercover Soviet foreign intelligence agent Sergei Ozerov - also US CIA officer Stan Bradley - becomes a witness and “participant” in a CIA conspiracy with the mafia to assassinate the leader of the Cuban revolution, Fidel Castro. A Soviet intelligence officer makes a desperately bold attempt to foil the assassination attempt on the Cuban leader. Finding himself in the training camp of the secret special forces "Mosquito" in Miami, Ozerov-Bradley finds a way to convey to Cuba the time and place of the landing on the island. The novel "Agony of the Doomed" is a continuation of the story of the adventures and exploits of the Soviet intelligence officer Sergei Ozerov, described earlier in the novel "On brink of the apocalypse."