The birthplace of the Mekong River seals the agreements of three different nationalities. Following the traces of running water, the two children approached step by step. The pursuit will never stop. Twenty years of time contain the thoughts of five people. Why? No matter the haggardness of the soul. Layers of doubts are uncovered one by one, shock, fear, and escape will still return to the beginning of the intersection, because union is the beginning of division, division is the end of union, and the starting point and end point have already existed on a horizontal line.