Season 6 ended with Raymond Reddington (Spader) visiting his former lover Katarina Rostova (Leila Robbins), who injected him with a syringe and kidnapped him. The trailer begins with that scene.
Once the FBI gets word "Red" is missing, Elizabeth Keen (Megan Boone) questions people about Red's whereabouts. They only tell her about "a Russian" but she knows that can only mean Katarina.
Back in Katarina's hideout, Red is chained up with a blood bag draining his fluids. Katarina is confident she can make Red talk. Red is normally the one in control. Even in captivity, Red could play games with the authorities. That's how his relationship with Keen and the FBI to find all the dangerous names on his blacklist began.
Katarina has shown up on The Blacklist before in flashbacks. Lotte Verbeek played the young Katarina, a KGB agent who crossed paths with Red and was involved with Keen's father.
Spader has earned two Golden Globe nominations for his portrayal of "Red" Reddington. The Blacklist stunt coordinator Cort Hessler won an Emmy in 2014 and nominations from 2015 - 2019.