“The Blacklist” Season 4 premieres this week, and it’ll finally reveal what happened after Alexander Kirk (Ulrich Thomsen) abducted Elizabeth Keen (Megan Boone).

Over the past three seasons, Liz’s parents, Constantine and Katarina Rostova (Lotte Verbeek), have been a mystery for not only the viewers, but also Liz herself. There have been many speculations regarding the real identity of her parents prior to Kirk’s truth bomb in “The Blacklist” Season 3 finale: Raymond “Red” Reddington (James Spader) was Liz’s real dad; her father was working for the Cabal; and Red killed her father and promised to look after her.

Not Just Another TV Site speculated that Liz’s father Constantine was a KGB agent, along with her mother Katarina. Her parents got into a physical fight when she was a child, which pushed 4-year-old Liz into allegedly shooting Constantine to protect her mother. However, Liz doesn’t remember this traumatic incident, and Red hasn’t provided her with concrete answers either, so there might be more to the story.

According to "The Blacklist's" Wikia page, Constantine apparently survived the shooting and later adopted the alias “Alexander Kirk.” After the fall of the Soviet Union, he reportedly became a businessman and took advantage of the broken economy by buying several mining and oil operations at a reduced cost. He fled Russia in 2002 after the government sanctioned a series of politically-motivated raids targeting his companies.

In "The Blacklist" Season 3, fans learned that Kirk is a billionaire who owns both legitimate energy companies and criminal enterprises. He also has connections to many key politicians across the globe, including presidential candidate Senator Robert Diaz (Benito Martinez), whom Red blackmailed in “The Blacklist” Season 3 into declaring Kirk as a terrorist supporter. In addition, Kirk and Red apparently go way back. The two nemeses have a long personal history that spans over two decades.

In “The Blacklist” Season 1, Red told Liz that he wasn’t her father, but since he’s known for keeping secrets, some viewers believed he could just be lying to her. However, last season, Kirk revealed that he was Constantine Rostova, Masha’s real father. And before you start thinking that this could be another ruse, “The Blacklist” executive producers Jon Bokenkamp and John Eisendrath previously confirmed to Entertainment Weekly that Kirk is indeed Liz’s long-lost father.

“I don’t know why we wouldn’t believe him. Red’s said before that he’s not Liz’s father. This man shows up in her life and says he’s her father. Liz should take him at his word. She thought she shot her father. It raises a number of questions, which is going to be the joy of Season 4,” said Bokenkamp, adding that the introduction of Liz’s father was a “big turn in the life” of the series.

“We cannot unpack a story point like she thinks she shot her father and then introduce a new element that completely negates it, because that would damage our relationship with the audience and their trust in the story that we’re telling. All of the things that you would point to and add up on one side of the ledger that might discount this guy’s story about his being her father, we are responsible for next year and in years to come to incorporate it into the story that we’ve already told,” Eisendrath told the publication in May, adding that the most questionable thing about Kirk is his motives for searching for Liz after over two decades.

Boone also teased that Season 4 could be the installment which reveals everything about Liz’s past, including her real connection to Red and her parents’ history. “What comes to light is that it’s not really Reddington bringing all of this upon her, it’s her own history and where she comes from,” she told EW earlier this week. “Something you start to realize through Season 4 is she was strapped with this from birth.”

Are you excited to find out what’s in store for Liz, Red, Kirk and the other characters? Make sure to watch “The Blacklist” Season 4 when it premieres on Thursday, Sept. 22 at 10 p.m. ET on NBC.