A fresh coroner's perspective, the unique premise of murals that kill, and a dual-thread conspiracy spanning the imperial court and the martial world. As for the story concept... (tapping the desktop absently) How about setting it in the height of the Tang dynasty? The clash between medicine and law was especially interesting in that era. The protagonist could be named Su Yan, a young coroner at the Court of Judicial Review. Give him a condition called "rainbow vision," which lets him see traces on corpses that ordinary people can't. But the ability gives him splitting headaches, making it a double-edged sword.
How about a string of connected murders as the main case? Each corpse is posed in the form of a torture scene from The Hell Transformation, and the killer is recreating murders from the mural! But the first case needs to be more subtle: it looks like a young woman hanged herself, yet Su Yan finds lapis lazuli powder under her fingernails, a pigment used only by court painters.
Every clue must come full circle: the lapis lazuli powder points to a painters' gang; the apprentice's muteness is the result of a failed drug trial; the coded notes in the old coroner's notebook are actually a plea for help. The key breakthrough in the investigation: Su Yan discovers that all the victims visited the same Taoist temple for "headache treatment," and an unfinished mural is hidden in its cellar.
