It's one of The Blacklist's most enduring mysteries but what did Red whisper to Kirk during his season 4 torture that spared his life? The Blacklist is NBC's long-running thriller series that kicked off in 2013. The show began with master criminal Raymond Reddington (James Spader, Stargate) turning himself into the FBI. Reddington also offers to help catch other wanted criminals, but in exchange for his help, he states he will only work with a young agent called Elizabeth Keen (Megan Boon).

The bulk of The Blacklist follows Red and Liz as they hunt down criminals, though the exact relationship between the two was a source of constant speculation throughout numerous seasons. Many fans predicted Red was Elizabeth's father - despite his denials - but in keeping with The Blacklist's twisty narrative, the real answer was more complicated. The show has been a reliable hit for NBC and has run for seven seasons thus far. It also spawned a short-lived spinoff with 2017's The Blacklist: Redemption starring Ryan Eggold and Famke Janssen.

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After teasing it out for years, The Blacklist revealed Reddington actually is Liz's father - but the real Reddington is dead, and the man she knows is an imposter who took his place decades ago. Liz shot the real Red as a very young child when he was attacking her mother Katarina Rostov, and he died of his wounds. The man posing as Red is Ilya Koslov, a friend, and lover of Katarina who has been protecting Liz throughout her life. One of the biggest mysteries presented by the show came in season 4 episode "Dr. Adrian Shaw: Conclusion," where Liz's stepfather Alexander Kirk - AKA Constantin Rostov - is about to kill Red, who then whispers something so shocking it stops him in his tracks.

Constantin_Rostov blacklist

For context, Kirk has a rare blood disease and needs transfusions to live, and wants to know if Liz is really his child since she'd be a good donor. This episode of The Blacklist had Red seemingly confess he is Liz's father - though since he revealed this under torture it wasn't known how truthful he was. When Red later whispers something in Kirk's ear he stops in shock, but to date, the show hasn't revealed what was said. The biggest fan theory was that Red revealed he WAS Katarina and underwent surgery to transform into Red, though creator Jon Bokenkamp himself seemed to dismiss this theory after the episode aired.

Other theories had Red telling Rostov that Katarina was alive after her supposed suicide, or that he and Rostov are related too. The Blacklist season 6 finally revealed that Katarina is alive, so it's likely this is what Red told Rostov. It's also possible he just told him some outrageous lie to spare his own life in the moment, but since Rostov's fate is still unconfirmed, he may reappear during season 7 and the series can finally reveal what Reddington whispered.

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