Cults are tightly-knit groups that are sometimes shrouded in secrecy. These groups may attract members by presenting them with flawed assumptions, such as the promise of religious salvation. Even while not all cults are religious, the vast majority of them adhere to a certain belief system that is exclusive to their group and does not allow members to depart from their guidelines in any way. Those who are part of a cult and wish to leave it are likely to have a difficult time doing so and may suffer psychological effects as a result of their departure. This research paper examines the background of the Japanese terrorist cult Aum Shinrikyo and its founder Chizuo Matsumoto before describing the terrorist acts the group committed, such as the deadly sarin petrol attack on the Tokyo underground system that left 12 dead and 5,500 injured. It also discusses the government's response to the attacks and the cult's plans. The paper also tries to cover the concepts of cults which are special sociological groups, the reasons for the formation of Aum cults, and their impact on society.