The male protagonist accidentally travels back to the Australopithecus era 4 million years ago. He must rely on his modern wisdom to survive, starting from eating insects and bone marrow, to slowly awakening the system, gaining certain enhancement abilities, and then befriending other apes to gradually form a small tribe. The protagonist is respectfully called the "Chieftain," and he leads his clan to live a vastly different life, utilizing modern wisdom to step-by-step unfold the technology of various eras.