Reddington is a fictional character from the television series The Blacklist. He is portrayed as a former criminal mastermind who surrenders to the FBI and offers to help catch high-profile criminals on his own terms. His extensive knowledge of the criminal underworld makes him a valuable asset to law enforcement. Throughout the series, Reddington forms a complex relationship with Elizabeth Keen, an FBI profiler. He often reveals secrets about his past and the reasons behind his actions, creating a web of intrigue and suspense. The show explores themes of loyalty, betrayal, and the blurred lines between good and evil.