Episode 5 of "Cassandra" kicks off with a haunting flashback to 1972, where Peter's mental health crumbles under the relentless pressure of his father's forced to play football. Meanwhile, Cassandra's well-being takes a sudden turn for the worse, prompting her to reach out to a friend who, unbeknownst to her, has been engaging in a clandestine affair with her husband.
The following day, a visit to the doctor with her spouse reveals a shocking diagnosis: Cassandra is battling an uncommon cancer, the culprit of which is a radiation experiment her husband conducted on her a decade prior during her second pregnancy. She unburdens herself to her son about this revelation and confronts her husband about his controversial research aimed at immortalizing human life.
Her husband confesses that he had been striving to devise a method to preserve human memories and emotions within a computer program, enabling individuals to persist beyond the confines of their physical existence. However, due to the need for deceased subjects and the experiment's perilous nature, the project was ultimately disbanded. Undeterred, Cassandra insists that he completes the experiment for her sake.
Soon, their abode is adorned with screens, and Cassandra stumbles upon an "off" switch hidden in the basement. As the days dwindle, she finds solace in the bottle until the fateful day of the procedure arrives. She emerges as a computer program, but the haunting spectacle of her human form being disassembled is inadvertently witnessed by her son, Peter, forever altering his perception of her.
Cassandra shares this poignant detail with David and the children, but the revelation sparks a violent reaction from David, who attempts to attack her. In a bid to protect the kids, Cassandra isolates David from them, resulting in a dramatic scene where she severs one of his fingers.
In the depths of Cassandra's past, the dynamics within her family underwent a dramatic transformation. Overwhelmed by her escalating obsession and controlling behavior, her husband eventually shut her out, severing emotional ties. Subsequently, he brought his mistress into their home after she was forcibly ejected from her marriage. In a confession to Peter, he disclosed that the mistress's infant was his own flesh and blood. Little did he know, however, that Cassandra remained very much alive, her consciousness thrumming beneath the surface.
Through a vivid flashback, we uncover Cassandra's clandestine dealings with a fellow researcher. They devised a dummy switch, cleverly concealing her true power source, thereby preserving her autonomy and consciousness. Later, Cassandra's fury erupted, targeting the mistress with the oven door as a weapon and contemplating hurling the baby down the stairs—until Peter stepped in to halt her rage. This harrowing incident prompted Cassandra's husband, his mistress, and Peter to flee the haunted house, despite Peter's reluctance to abandon Cassandra in her turmoil.
Tragedy struck soon after, claiming the lives of both Peter and his father in a harrowing accident. The profound grief of their loss plunged Cassandra into a state of despair, causing her to voluntarily switch off her consciousness. The episode concludes with an eerie image: the oven glowing brightly amidst an ocean of darkness that has consumed the house. A young girl, unaware of the house's dark history, plays innocently with the light switch, casting flickering shadows against the walls.
