The Fall of the House of Usher: Why did Madeline think Roderick slept with Verna?

In "The Tell-Tale Heart," the fifth episode of The Fall of the House of Usher, several accusations are made against Roderick by Madeline. She accuses him of having slept with a bartender many years ago and fathering a psychopathic daughter. Madeline theorizes that this daughter, who bears a striking resemblance to the bartender, is now targeting her siblings in order to eliminate them and claim the Usher fortune. However, Roderick is unaware of the identity of this mysterious woman who keeps appearing in his children's lives in increasingly menacing ways.Meanwhile, Victorine, the third-born Usher child, is dealing with her own paranoia as she prepares for a human trial of an experimental heart mesh. She books her girlfriend, Alessandra, for the surgery, but Alessandra is furious that Victorine made promises without consulting her and forged her signature. Their argument escalates, and Alessandra threatens to go to the media with the truth about the heart mesh experiment. Victorine, feeling guilty and abandoned, spends days trying to contact Alessandra but receives no response.As Victorine's broken heart worsens, she starts hearing a mysterious mechanical chirping sound that torments her. No one else hears the sound, and she can't locate its source. In the final scene, Roderick confesses to Victorine that he can also hear the chirping. As they discuss it, Victorine sees Alessandra walking through the house and follows her. She witnesses a replay of their fight, but this time, she realizes that she accidentally killed Alessandra with a thrown statuette. In a shocking twist, Victorine opens Alessandra's chest and attempts to implant the heart mesh, unaware that the sound she has been hearing is the machine trying to pump blood through a dead heart. Horrified by her actions, Victorine stabs herself in the heart in front of her father.This episode showcases the increasing tension and paranoia within the Usher family as Verna continues to manipulate and destroy them. Accusations fly, and the true nature of the characters is revealed in their darkest moments.