Maxim Serov has already managed to do a lot: to unite the tribes, establish a settlement, build a ship and repel numerous enemy attacks. With the help of his friends and associates, Maxim leads his Rus people to civilization, introducing new developments and achievements. The production of steel and pig iron has been mastered, agriculture and animal husbandry are developing. Our compatriot astronaut managed to escape from Neanderthal captivity and, after long adventures, to get to a loving family and a devoted tribe. But the Plage settlement, founded on the Cro-Magnon migration route from Africa to Europe, will always be in danger. And Max decides to colonize the islands in order to save his family. At sea, he stumbles upon a reed boat containing two unconscious people. What tribes have mastered shipbuilding, who dares to challenge Maxim Serov, the lord of the sea?