An adventure thriller, Johnny Gaddaar revolves around the lives of five men from the city's notorious section. The eldest is more than 60 while the youngest one is in his 20s. This group is involved in various legal and not so legal activities. Their lives take a turn when one of the gang members, Seshadri, gets an offer to make a fortune in four days. All the gang members are willing to participate since this deal would earn them a fortune in a very short time and might be their ticket to the big league. The youngest member Vikram plans to disappear to some unknown city and start afresh with his girlfriend Mini. But a better idea strikes him...