The Blacklist season 6 finale confirmed the fate of a major character. The Blacklist revolves around wanted criminal Raymond Reddington, who suddenly turns himself into the FBI one day. Red (James Spader, Stargate) offers to help them track down other wanted criminals on his so-called "Blacklist," but he will only work with rookie agent Elizabeth Keen (Megan Boon, My Bloody Valentine 3D) in exchange.
In addition to hunting notorious criminals, secrets from Reddington and Elizabeth's pasts becoming major plot points. The Blacklist has been a huge success for NBC and is returning for a seventh season in October 2019. This is thanks in large part to Spader's insanely charismatic central performance, though Boon and the other members of the cast keep it grounded. The show also produced a short-lived spinoff with The Blacklist: Redemption, which focused on Keen's husband Tom (Ryan Eggold, New Amsterdam).
The central mystery of The Blacklist for six seasons was the exact nature of Red's relationship to Liz. The natural theory is he's her real father, and the show had a lot of fun twisting and subverting those expectations over the years. It was finally revealed in season 6 that yes, Raymond Reddington IS Elizabeth's father - but the man she knows isn't Reddington. He's Ilya Koslov, a friend and sometime lover of Liz's mother Katarina Rostova. The real Reddington was shot by 4-year old Liz when he attacked her mother, and Koslov took his identity, taking plastic surgery to transform into the man.
Katarina was a KGB agent sent to seduce and keep tabs on the original Reddington, but after his death, she seemingly committed suicide by walking into the sea. Being The Blacklist, there's naturally a twist, with season 6 finale "Robert Diaz" revealing that not only was she a double agent for the shadowy Cabal, but that she's still alive. When Red learns this he tracks her down to Paris, where he sees her on a street. She approaches and kisses him - before injecting him with a syringe. A van pulls up and drags Reddington away, with this cliffhanger suggesting they won't have a happy romantic reunion in season 7.
Stills from The Blacklist season 7 reveal she's torturing Red for information, so it will be interesting to see if she's a full-blown villain or something else is going on. This reveal probably wasn't a big surprise to longtime fans, since there was always an air of mystery regarding Katarina's fate. The only question is how will Liz react during their inevitable reunion?