10. The Cold War

To bring The Machine out of hiding, Samaritan showcases its strength by eliminating crime in New York City for a whole day. John finds out that Samaritan has learned how to deal with irrelevant numbers and has managed to prevent a series of crimes which would otherwise be taken care of by The Machine. Samaritan's actions leave Harold and his team with a difficult choice. When The Machine decides not to communicate with Samaritan, Samaritan changes course, bringing New York City to a halt by allowing crime to dramatically increase.

When The Machine agrees, Root (acting as The Machine's voice) meets with Samaritan's representative, a young boy. It becomes clear that The Machine will not back down, while Samaritan is set on destroying it. Shaw leaves the Subway to help Root and the others while Samaritan engineers a stock market crash on Wall Street. A series of flashbacks show Greer's past as an MI6 agent. When Greer is assigned to kill a KGB agent, he discovers that the KGB agent is also an MI6 agent and that his deputy director, Blackwood, is a double agent. Overcome with anger, Greer kills Blackwood and severs his ties with MI6.