Red (James Spader) and Mr. Kaplan (Susan Blommaert) will surprise viewers, as they work together to save Liz (Megan Boone) from danger in this week's episode of "The Black List" season 4.

In the trailer for episode 20, Liz gets attacked by a mercenary, known as "The Debt Collector," who sprays a chemical on her face, which makes her unconscious. Red tries to find a way to save Liz before the mercenary kills her. He asks the help of Mr. Kaplan, despite their existing conflict. He knows that it is only when they unite and set aside their differences that they can find and save Liz from her captor.

Mr. Kaplan agrees to help Red, and she tracks down the place where Liz is being held captive. They infiltrate the mercenary's lair and everything gets chaotic after that.

Now, the question is: Who hired the mercenary to kill Liz? According to CarterMatt, given that Mr. Kaplan's actions seem to suggest that she is trying to protect Liz, it is not likely that she is the one who wants her dead, unless the mercenary's job is just to abduct Liz and not kill her. It also quite unlikely for a new villain to suddenly pop up this late in the season.

In the previous episode, Mr. Kaplan tried to bring back Liz's memories involving Red, which were erased by a "blacklister" named Dr. Bogdan Krilov (Rade Serbedzija) a few years ago. Getting Liz to remember everything was part of Mr. Kaplan's plan to take down her nemesis, Red, who also warned Liz that she was being manipulated.

On the other hand, as per the synopsis released by the network, the upcoming episode will also feature Ressler (Diego Klattenhoff) facing an unanticipated problem when he tries to stay ahead of Agent Gale's (Enrique Murciano) investigation.

"The Blacklist" season 4 airs Thursdays at 10 p.m. EDT on NBC.