For several millennia, the supercivilizations of Aggrs and Forsails have been at war with each other, choosing the Earth as the arena of secret battles. Time travel and “rewriting” the past are one of the methods of this war. But history is created by the hands of earthlings themselves, and that is why the aliens need Andrei Novikov and his friends. But they do not want to be a blind tool of an alien mind... By defeating the Aggro civilization, Novikov’s team will finally prove their independence. But, as a result, the Earth has changed so much that the heroes of the novel cannot exist in this altered reality and are forced to stay in the timeless residence of the Forsails - the Castle. The way out is suggested by the foresail resident Anton - another reality, another time... Having captured and recruited Sylvia Spencer, a resident of the Aggros on Earth, who has a lot of useful information, they begin their game, the main events of which unfold at the beginning of the 20th century, where, after several trips through time and our contemporaries find themselves in space. The cards are dealt - the Great Game begins...