In her watery abode, Priestess Nero fell into eternal sleep for many years. She left behind only one thing - a book containing instructions for her Marr people, the aquatic inhabitants of the endless ocean. All the Marrs never cease to honor the honor of their beloved goddess, but the old traditions are gradually beginning to be forgotten. The Marrs of the northern region have put forward a terrifying theory: Priestess Nero has in fact been dead for a long time. From now on, the life of the people of Nero hangs in the balance of death, because a dishonest, fratricidal war is approaching, which will reverse all the currents that previously bound all the Marrs with one blood. In the dark depths of the abyssal zone, the judge of the entire ocean is awakening, ready to destroy any of the remaining two cities, if the coming war will not be stopped in time. But will the entire ocean perish if the only species of intelligent creatures inhabiting it is destroyed? Will the Marrs themselves perish if they begin to move away from their past idols? What can save the ocean from death?