As humanity first sets foot in the interstellar age, they encounter the Oskerk civilization, leading to the first interstellar war. As territories continue to fall and fleet casualties mount, humanity is eventually forced back into the solar system. In the 58th year of the Federation, Lin Fan, a time traveler from Earth, graduates from the Interstellar Military Academy and joins the Federation fleet. From this day on, humanity's counterattack begins. Starting from the Milky Way galaxy and to dominating the entire universe, humanity's steps will never stop. This is the story of a time traveler leading humanity's counterattack.