A wave of professional jealousy and high-stakes tension enters the Forger household with the arrival of Fiona Frost, a cold, calculated WISE agent codenamed Nightfall. Working undercover alongside Loid at his hospital, Fiona secretly harbors deep romantic feelings for Twilight and firmly believes she would make a far more efficient, ruthless wife for Operation Strix than Yor. Looking to prove her absolute superiority, Fiona pays a surprise visit to the Forger residence to evaluate Yor's domestic performance. Her presence triggers a deep wave of insecurity in Yor, who begins to question her worth as a mother and wife, forcing Loid to step in and carefully balance the emotional stability of his fabricated household.