Lhong Klin Chan

Wanrak, an investigator, gets transferred to her small hometown in order to investigate the homicide of Chankrapor who was murdered and buried underneath a Chan por tree.
There, she meets the forensics doctor of the area who, although he likes to question her intelligence, teams up with her in order to find the murderer. Joining them is Trichai, a handsome young lieutenant who's always ready to help.
The catch of this case is that the deeper you search, the thicker the fog becomes.
(Source: thaidramatic_update; edited by Soju at MDL)