In the next episode of "Knightfall," Isabella (Sabrina Bartlett) discovers who betrayed her by revealing that Prince Luis of Catalonia (Marcos Franz) had spent the night in her chambers before their marriage.

The trailer for the upcoming installment, which is titled "The Pilgrimage of Chains," was just released recently, and it shows Isabella exploring the secret passageways in the castle. She notices that the winding maze is used by her supposed confidante William De Nogaret (Julian Ovenden). When she ventures further into the passageway, she realizes that it passes by her chambers and that there is a secret hole where anyone can look into to see the inside of her quarters. Isabella is shocked and finally realizes that the person who reported about her secret dalliance with Prince Luis was De Nogaret.

Isabella is disgusted by the thought and confronts the scheming traitor. She slaps De Nogaret hard in the face and curses at him to no end. "Before you make assumptions, let me explain," he pleads with the furious Isabella. It remains to be seen how the cunning palace official will try and get out of this sticky situation.

In the meantime, the Templar Landry (Tom Cullen) is kidnapped by a mysterious group. They place a noose around his neck and stand him on a barrel. If he falls from his position, he could hang and die.

In the last episode, Isabella and Prince Luis were about to get married at their ceremony when an assassin disrupted it and attempted to kill the couple. Landry was able to block the arrow's path and save Luis, but Isabella was taken by the other henchmen. Luis saved Isabella, but he sadly died in the process.

"Knightfall" season 1 episode 6 will hit the airwaves on Wednesday, Jan. 10, at 10 p.m. EST on the History channel.