Lu Chenzhou, a forensic trace-evidence expert, is reassigned to a grassroots post after his partner is killed. There, he is paired with Gu Yunshu, captain of the criminal investigation squad. Together with technician Zhou Xiaoman, they solve ten baffling cases that seem unrelated, with help from their outside support team: crematorium worker Song Laogui, rideshare driver A Tang, and pet funeral director Su Wanqing.
But as the investigation deepens, Lu Chenzhou discovers that every case contains one “extra trace”: a fingerprint that does not belong at the scene, hidden GPS coordinates, or trace elements that should not be there. All of these traces point to someone who should have died three years ago: his best friend from police academy.
Main cast:
Lu Chenzhou (male lead, 35): A forensic trace-evidence expert, solitary and obsessive, with a fastidious attitude toward physical evidence. Nicknamed “Lu the Ruler.”
Gu Yunshu (female lead, 29): Captain of the criminal investigation squad, decisive and action-oriented.
Zhou Xiaoman (technician, 26): A rookie forensic trace examiner, diligent but clumsy, and the reader’s “eyes.”
Outside support team:
Song Laogui (60): A crematorium worker, skilled in bone analysis and reverse analysis of physical evidence.
A Tang (28): A rideshare driver and former reconnaissance soldier, with an encyclopedic knowledge of the roads.
Su Wanqing (32): A pet funeral director, chemistry enthusiast, and expert in microscopic evidence.
