Spoiler for Shutter Island

Shutter Island is set back in the 1950s, just after World War 2. It's set on an Island so none of the patients can escape from this mental island.  There is a patient on the island who pretends to be somebody he isn't. The doctors let him believe that he is someone he isn't to see whether he can remember who he really is and if he remembers why he is on this island. He plays the role of a detective investigator and is someone called Eddie, he has a work partner called Chuck who is played by one of his doctors. They create this fake escape where a patient escapes, but they only way off and on the island is by ferry and that's all overlooked, so there is really no way of anyone escaping. The man who believes that he is Eddie has been told that he is asked over to the island to try and gain information of an escaped patient. Throughout the film Eddie has flash backs to this woman who was his wife, at this point we are told that his wife died/got killed by a man called Andrew. He also images a little girl which we later discover to be his daughter, whenever we see him she always says 'you should've saved me'. It doesn't fully get summed up until the end when Eddie realizes he is actually Andrew and was brought over to the island because he killed his wife who drowned his three children. The wife tries to blame her drowning the children on him not getting her any help for her illness.