'The Blacklist' season 4 spoilers news: Liz's mom coming back for 4th installment? Spin-off in the works?

There is barely a month and a half to go before "The Blacklist" returns to the small screen for its fourth installment. At this point, only bits and pieces are being given away concerning the upcoming season's arc, but it looks like season 4 of NBC's top rating crime thriller is going to be one exhilarating and thrilling ride.

During the season 3 finale, it was established that Liz (Megan Boone) is alive and that she only faked her death to get away from Red (James Spader). Alexander Kirk (Ulrich Thomsen) was also revealed as Liz's biological father, and baby Agnes has gone missing.

Speaking to Zap2it, creator Jon Bokenkamp teased that "The Blacklist" season 4 isn't going to lay off on the suspense. He likewise said a spin-off involving Liz's husband, Tom (Ryan Eggold) is in the offing.

"We pick up in the immediate aftermath of where we left off in Season 3, and it's an absolute roller coaster," Bokenkamp said. "It's a mess. It's frenetic and dangerous and the stakes are incredibly high."

He added, "We're really on a freight train of storytelling. This season is similar [to Season 3] in that we're starting in such a really nice place, story-wise, with some great energy. I think it's going to be a really fun season, I think people are going to love it."

Apparently, the fourth season would see Kirk as a major character with his own "surprising" and "refreshing" storyline. Bokenkamp also said that Mr. Kaplan (Susan Blommaeret) would be back and would have to deal with his betrayal of Red.

As for Liz's husband, Tom, the creator said he would still be part of the fourth season, although a spin-off is in the works. It looks like the production team would be focusing on the problems raised by the third season first before they go full on with the spin-off.

Meanwhile, Entertainment Weekly has confirmed that Lotte Verbeek would be reprising her role as Katarina Rostova, Liz's mother, the former Russian spy whom according to Red is dead. There is a possibility that something happened between Red and Katarina in the past, something that remained a mystery until the closing episodes of season 3 when Red was seen cavorting with Katarina's ghost.

Whether Katarina would be back for "The Blacklist" season 4 as a ghost, a breathing human, or in flashbacks remains to be seen. At any rate, it would be exciting to see how Katarina's arc would unfold.

"The Blacklist" returns Thursday, Sept. 22 at 10 p.m. ET/PT on NBC.