The underground dark river was pitch-black, with only the light from Yan Fei's diving suit breaking the darkness. If it were an ordinary person entering this dark river, they would have already panicked due to the darkness and disorientation. However, Yan Fei had already used quantum radar to draw a 3D map of the underground conditions of Beijing and stored it in the Auxiliary Brain. So even though he was diving more than a hundred meters deep in the underground dark river, Yan Fei didn't feel the slightest bit nervous.
All he had to do was follow the directions indicated on the 3D map that appeared in his mind. With the engine's help, Yan Fei moved very quickly underwater, and along the way, he encountered several large fish and snake attacks, the likes of which he had never seen before. However, Yan Fei was so strong that he easily killed these fish and snakes.
