
The story continues from Saw (2004). The psycho guy suffering from cancer and escapades from death numerous times is involved in a repeated mental and physical torture like in Saw.
Detective Mathew is famous in his job for catching many drug addicts but always bails out his teenage son. The movie open with a murder and a message for Mathew on the ceiling. He tracks down the criminal but has a bigger job at hand which he can watch only on a series of monitors. He has time till 6:00 in the evening to save his son and others who are among the eight kidnapped.
All the eight have something in common.
Does he save his son or what happens forms rest of the movie.
There is one other person who is also carried over from earlier sequel, Amanda. This one can understand when she says “I have played it earlier”.
The best part is the conversation between Mathew and the psycho, where the psycho teases him and provokes him to the max. But Mathew cannot kill the psycho to save his son. In the heat of the moment, Mathew never gives second thought to what the psycho says “Your son will be safe”.
As a viewer if you watch carefully, you can judge what will happen next. But there is no relation between the sequels except the tourture part.
In this sequel, there is more characterisation and the characters are built to give a good understanding of their background unlike the earlier.
This movie is also not for the faint hearted. Though it would not scare you as much as the earlier sequel. But a definite watch is recommended.

You really seem to be a movie buff. Heavy viewing.
sort of yes, hiren