Years ago, there was a Cold War. It went on for decades until an agreement was signed. Those emotions and dark thoughts that caused such terror and hatred would be banned, and so there would be peace. It was declared that our emotions were dangerous, and so when people came of age their hearts were removed and replaced with mechanical substitutes. These mechanisms were hooked up to the nervous systems of their hosts so that when dark thoughts were detected, the mechanism would electrocute them. In time, the host was trained not to think those thoughts anymore. This is how the population of our world was controlled. There was no war. There was no anger. There was only peace. Until the 'Blackout'.