A brilliant detective is forced into early retirement after losing eyesight. Making ends meet by solving cold cases for reward money, he teams up with a rookie lady inspector to solve a case from her personal past.

In "Hot Summer Days" a hot summer heat wave engulfs the Chinese territory, while the movie covers the lives of various characters during that time. There's chaffeur Wah who tries to woo foot masseur Li Yan via text messages, air conditioner repairman Ah Wai interested in biker girl Ding Dong, a master sushi chef who spurns the love of writer Wasabi, country hick Da Fu who tries to impress teddy bear factory worker Xiao Qi Angela Baby by standing out in the hot noon sun for 100 days, & photographer Leslie Guan & assistant attempting to track down a woman who they believed cursed the photographer into blindness ...