The novel from the master of Russian science fiction continues the “Space Explorers” series. Patriotism, scientific concepts and valiant heroes. Darislav Volkov leads the next expedition, but now the Salyut escort is sent to the Castle of Dragons, raised by earthly pterosaurs in the depths of the dark Universe. Vsevolod Shapiro, a physicist from the “neighboring” metaverse of the Multiverse, studies Darkness and works on the theory of the anti-universe, but he faces another, secret task. The portal leads Volkov, Shapiro and their companions to a strange place where weapons and combat vehicles are not produced, but are grown from peculiar “spores”. Will they be able to go back? Will they be able to cope with the dragons that suddenly emerged from suspended animation? The cold mind of Tmir planned to cleanse our Universe from the “dirt and garbage” of other civilizations. But earthlings are capable of solving any problem that threatens their homeland.