Chinatown (1974). Based in the 1920s era, a private investigator is hired to investigate an engineer working for the LA Water and Power company who is suspected of cheating on his wife, later to find out the woman who hired him is not the engineer's real wife. The purpose was to publicly discredit the engineer and cost him his job. After the effort failed, the engineer is found murdered and dumped into a local reservoir. The private investigation leads to a grand criminal conspiracy relating to a large dispute between the LA Water and Power company and the murdered chief engineer, who ended up refusing to build a new dam to divert water (presumably meant to stop LA's massive drought crisis). What is uncovered during this investigation involves massive corruption, graft and fraud: a scam to milk LA taxpayers while enriching new land owners who exploited the drought to buy up farm land for pennies on the dollar, before enriching themselves by diverting water with a new damn over to their new properties using taxpayer money from LA.