'The Blacklist' season 4 release date, spoilers news: Katarina Rostova to appear again

There's one more reason to be excited about "The Blacklist" season 4 and that is the return of "Borgias" alum Lotte Verbeek as Katarina Rostova, Liz's (Megan Boone) ever-elusive mother.

Entertainment Weekly first broke the news and even got to speak to executive producer Jon Bokenkamp, who shared more details about Verbeek's return.

"In the first two seasons, we used pictures and a few fragments of memory, but Lotte brought Katarina to life in Cape May," Bokenkamp said.

"The fan response to that character has been great. The episode itself was a departure, but we've found some really interesting story opportunities as a result," he continued.

Bokenkamp did not specify in what form Rostova will appear in "The Blacklist" season 4 as in the past, she was only portrayed in abstract form.

Last season, Red (James Spader) saw her in his vision as he mourned Liz's apparent death. It will be exciting to see Rostova in the flesh and fans hope it will finally happen in "The Blacklist" season 4.

Verbeek is only booked for a couple of episodes in the next season. It remains a mystery as to how she will appear, but it is believed that fans will learn more about the mysterious character.

In "The Blacklist" season 4, Red will race against the clock to save Liz, who is in the hands of his nemesis Alexander Kirk (Ulrich Thomsen), who claims to be her father.

Last season, Liz faked her death in an attempt to stay away from Red and live a normal life with her family. However, Kirk entered the scene and brought her right into the world of danger and also to Red's radar.

Red feels betrayed about what happened, but it appears that in "The Blacklist" season 4, he won't think twice about going after Kirk to save Liz. Because of this, his relationship with her is expected to be explored.

"The Blacklist" season 4 will premiere Thursday, Sept. 22 at 10 p.m. EDT on NBC.