Derivation:viewer of abyss is a suspense‑themed visual novel. A mysterious girl transfers into high‑schooler Deng Ning’s class. A string of serial killings plagues the city he lives in. Worried for her safety, Deng Ning offers to walk the girl home. He never suspects that the girl he tries to protect is the mastermind behind the murders. Killed and certain his life has ended, Deng Ning opens his eyes again. He has been sent back to before the tragedy — death has granted him the power to reset time. Trapped in recurring time loops, Deng Ning investigates time after time, gathering clues and chasing the truth to stop the slayings. As he digs deeper, he realizes the serial murders are only the tip of an iceberg. The loop itself hints at a world‑shaking secret far beyond ordinary understanding. There are four distinct yet interconnected story routes in the game. No single route reveals the whole truth. Only by piecing together fragments from every route can players unlock the door to the ultimate answer.