Kaisi Ye Paheli is a murder mystery set in Kalimpong where a 19-year-old student, Ishita is found dead in her hostel room after consuming a poisonous sweet. To solve the case police office Uttam (Sukant Goel) is brought in along with his fellow assistants, Gogoi (Rahul Nawach Mukhia) and Tamang (Chittaranjan Giri). Soon the investigation reaches a roadblock which leave the police clueless. That’s when Uttam unwillingly turns towards his widowed mother (Sadhana Singh) to help him solve the case. Uttam despite having a strained relationship with his lonely mother, who is an avid reader of detective fiction and sees what others overlook, gradually exposes not just new clues but the fractures within their own bond. What happens next forms the remaining plot of the film.