Inspired by real police reports, Uyir is a police procedural thriller that follows a series of mysterious deaths in Kannur. Ajeeb Rahman is a probationary police officer with the Kerala State Police, currently serving at the Dharmadom Police Station. One day, he receives a call about a body discovered in a well, unrecognizable due to decomposition. Ajeeb and his colleague, Officer Joy, are soon drawn into a dangerous investigation to uncover the motive behind the murder and identify those responsible.

As the investigation progresses, Ajeeb is forced to confront his own inner demons when the case brings back painful memories of his sister's disappearance at a train station.

The film is a gore-filled, mystery-driven crime laden plot thriller in which Ajeeb must travel across state borders to track down the criminals and dismantle a larger murder network. But as the investigation unfolds, he realizes that these murders are far more complex than they first appear.