Karai (2011)

Guru comes to meet Raj over a weekend and he introduces him to his 3 friends - Vishnu, Sam and Jeeva. Guru also happens to meet Vidhya, on whom Sam has a crush. Later Sam watches Guru and Vidhya at a restaurant which irks him, leading him to have a heated conversation with Raj about the motives of his friend. Following this Sam is murdered. Over the course of the next 2 days, the two other friends are also murdered under mysterious circumstances, living Guru and Raj in a conundrum as to who is the killer.