The long wait for the next episode of "The Blacklist" season 4 will soon be over, which means that fans of the series will finally find out why Dembe Zuma (Hisham Tawfiq) tried to poison Red (James Spader) in the first half of the season.

According to the synopsis of the episode titled "Dembe Zuma," Red and the rest of the Task Force will finally get a lead on Dembe's hiding place after several weeks of hunting his former closest ally.

But as the group grows nearer to the former Muslim freedom fighter, the group will discover that Aram (Amir Arison) is missing. On the other hand, the synopsis also mentions that Dembe knows that Red is already closing in, which is why he will have to make a calculated risk.

The synopsis does not mention why Dembe betrayed his foster father. However, hopes are high to see him provide a good explanation why he had to do it in the first place.

The episode will be aired on NBC on Thursday, April 20, at 9 p.m. EDT.

Meanwhile, reports claim that Liz (Megan Boone) will have to rely on Red to get a better picture of her past that she can vaguely remember from her own memories.

According to reports, Liz will wonder if what she remembers really happened in real life, or if her memories are just manipulated.

Other reports claim that in the episode titled "Dr. Bogdan Krilov," which will air on May 4, Red and the Task Force will discover a new Blacklister who owns a device that can manipulate someone's memories. It can be speculated that Liz might have run into that Blacklister in the past, which means that her memory might be rigged by the same person.

Because of the discovery, Liz might question her already vague memory and become more skeptical if what she remembers are real or not.