the story is about a patient who suffers from cancer . his name is Jhon but police knows him as Jigsaw. he is an engineer and he wants punish the people who don't know the value of life. he catches some people and forced them to scarify sth for survive. People like snitches, betrayers , the ones who torture themselves , criminals … he has a lot of information about his victims and their private life. At the fourth part you'll find out how he gains these information. The punishments are too severe: cutting foot by a saw, bringing out one's eye, entering into a hole filled by syringes … and the message of movie as I think , is knowing the value of life