A double agent is a spy who secretly works for two different intelligence agencies, often representing opposing sides. This means they gather information for one agency while secretly providing that same information to the other. Double agents can be very dangerous because they can mislead both sides, creating confusion and mistrust. These spies often take great risks, as being discovered can lead to severe consequences, including imprisonment or even death. Famous examples of double agents include Kim Philby, who worked for the British intelligence while secretly spying for the Soviet Union. Their actions can significantly impact international relations and security.