The night on the Mekong River is so dark that it can eat people. Ajie, who has been running a boat for seven years, was delivering dendrobium to Laos for his boss Jinghong, but he was turned into a deadly poisoner. He was intercepted and killed by unknown gangs, and later surrounded by the marine police. He turned from the boss of the boat to a desperado overnight.
In the iron box dug out from the bottom of the boat, there were old photos of his father who had been dead for fifteen years, as well as the badge of the 1987 Lancang-Mekong Channel Survey Team, and a hand-drawn secret map labeled "Ghost Crying Beach", which dragged him into a puzzle that lasted three generations.
The scorpion Buddha amulet, the military kettle in the ghost raft, the words "Don't believe the photos" engraved on it, and the words of the Wa village old man "Your father is still alive and has been waiting for you for fifteen years" tore open the darkness on the border.
The three sides of China, Laos and Myanmar were exposed, and the shadow of the "Deep Blue" top-secret project in 1964 made Ajie realize that the Mekong River he had been running for seven years had never been a waterway. It was a net that entangled three generations of the Chen family, and the door under the water in Guiwei Beach was waiting to use his blood to open the truth that had been sealed for thousands of years...
