Rookie cop Souvik joins Kanaichoron, a laid back, unambitious senior inspector at the Department of Unusual Cases. Meanwhile, a mysterious stranger is terrorizing the villages of Bengal by killing off hundreds of sparrows.

Forensic expert Mrinalini helps in the investigation. As the cops try to understand the motive of the killer, a veteran informer is their only hope.

The sparrow killer strikes again and leaves back a clue that makes Kanaichoron and Souvik see some light at the end of the tunnel. Also, the duo finally identifies a pattern in the serial killings.

A cat and mouse game begins between the elusive killer and the cops. Meanwhile, Souvik accidentally uncovers a vital part of the puzzle.

Some unexpected incidents throw the duo off the rails. Souvik starts to question Kanaichoron’s credibility and wonders if he is wasting his career working on an apparently pointless case.