Police officer Zhou Tiangui and his three teammates traveled back in time to the Xuanhe period of the Northern Song Dynasty. They moved around, battled wits and courage with various historical figures, and tried their best to avoid the humiliation of Jingkang. However, the wheels of history rolled by and sometimes did not depend on personal will... This book strives not to fall into the trap, and through time travel From the reader's perspective, it is close to the style of the times in the late Northern Song Dynasty, showing the interest of history, and focusing on restoring the logical starting point and basic context of historical events such as the Fangla Uprising, the Maritime Alliance, the alliance with the Jin Dynasty to destroy the Liao Dynasty, and the Jingkang humiliation. I hope that it can cross time and space with readers who like Song history and create sparks.