Former research elite Qin Mingyue applies to a bankruptcy-threatened housekeeping company carrying chemical reagents, turning routine cleaning into a hardcore crime scene investigation. Using scientific methods such as ultraviolet light and chemical titration, she successively cracks mansion stain mysteries and antique calligraphy fungal crises. However, in high-end housekeeping competitions, a sudden chemical fire and client regulatory accusations become her greatest tests. Facing severe external skepticism and a research institute reinstatement invitation, Qin Mingyue must prove herself with flawless cleaning techniques, finding her true belonging in the bustling human world beyond the microscope.