During the Daliang period, the emperor established the "Anhe Division" - a secret investigation agency independent of the Ministry of Justice and Dali Temple. It specializes in investigating serious and unsolved cases involving the court, Jianghu, and the royal family. It is known as "the eyes and ears of the emperor, and the hidden blade of the court."
Fifteen years ago, Shen Canglan, the first head of the Underwater Division, was accused of colluding with the Northern Enemies and had everyone executed. The Underground Division was subsequently abolished and all files were burned. Fifteen years later, the Dark River Division was rebuilt and recruited a group of young people with different backgrounds - a taciturn deduction genius, a fierce and decisive female head catcher, a gentle poison doctor, a cold-faced assassin, a money-hungry and death-phobic mechanic, an all-round intelligence queen, and the current scheming boss.
The first case they took over seemed to be just the mysterious death of a shipping official, but it actually involved a huge smuggling network behind it. And when they peeled back the truth layer by layer, they found that the depth of each case vaguely pointed to the truth of the treason case fifteen years ago——
What exactly did Shen Canglan find out back then? Who was the person who framed him? And how many unknown secrets are there within the Dark River Division?
From the streets of Luojing to the depths of the rivers and lakes, from the imperial court to the beacon fire at the border, seven people, seven colors, and seven lives entangled by fate, will walk step by step on this road called "Underground River" towards the answer that has been buried for fifteen years.
