Lock Up follows the lives of sub-inspector Moorthy and constable Vasanth . There is also Ilavarasi , a hard-nosed police inspector who is put in charge of the station the two men work at after the previous inspector, Sampath, is murdered.

When a simple middle-class girl’s family wins a car in a raffle, chaos ensues as various parties claim ownership, forcing her to navigate a darkly comedic web of financial crisis and unexpected events.