The Fall of the House of Usher: Why was Madeline making noise in the basement while Dupin and Roderick were chatting?

In the final episode of The Fall of the House of Usher, titled "The Raven," it is revealed that Madeline Usher and Roderick Usher have made a deal with Verna, a supernatural entity representing death itself. They offer their bloodline in exchange for power, wealth, and everything they desire. However, Madeline eventually becomes desperate to escape her fate and tries to find a loophole to continue living. As she and Dupin are chatting in the living room, Madeline makes noise in the basement.The reason for Madeline's noise in the basement is that she is trying to fulfill her end of the bargain with Verna. She knows that she must die, as agreed upon in the pact, but she doesn't want to go down without ensuring Roderick also fulfills his part. Madeline tries to convince Roderick to kill himself, but when he refuses, she takes matters into her own hands. Madeline poisons herself and embalms herself like an ancient Egyptian queen, ensuring her death. However, her rage and determination to not let the men who have benefited from her suffering live on drives her to rise from her sarcophagus and choke Roderick to death in front of Auguste. In this moment, Madeline meets her own demise as she falls off the building.With the Usher family completely extinguished, the epilogue reveals what happens to the remaining characters. Juno, who has inherited Fortunato Pharmaceutical, dissolves the company and uses the money to start a foundation to help people dealing with addiction. Arthur Pym, who refused the deal with Verna, becomes the only person arrested in the government's case against Fortunato, thanks to the evidence collected by Camille. Auguste retires and lives a peaceful life with his family. He visits Roderick's grave and leaves a tape recorder with their recorded conversation, symbolizing the futility of their actions now that they are all gone.As for Verna, she takes the form of a raven and visits the graves of her victims. She returns objects that remind each individual of their lives and deaths. Prospero receives his mask from the acid bath, Camille gets her cell phone, Leo receives Pluto's collar, Victorine is given the heart mesh, Tamerlane receives a golden bug, Frederick gets a bag of cocaine, and Roderick and Madeline receive an empty whiskey glass and sapphires respectively. Finally, Lenore, who is considered the best of them, receives a feather and a white rose as a tribute to a life well-lived.In conclusion, the noise made by Madeline in the basement while Dupin and Roderick were chatting was her fulfilling her end of the pact with Verna. Despite her attempts to escape her fate, Madeline ultimately embraces her role in the destruction of the Usher family.