 Robert McCall is a former spy, who has left the Agency that he works for. He is trying to make a normal life and also establish a link with his estranged son. He also has to deal with his former superior, who needs his help every now and then, which is why he left the Agency and people from his days as a spy. But for whatever reason, he takes out an ad in the newspaper that states "Got a problem, need help, odds against you, Call The Equalizer". And he gets all sorts of calls from people who need help, people who tried to get help from the police but cause of lack of information, or probable cause, or shortage of manpower, can t help them. So they turn to him.