The narrative shifts to a "Before" timeline. Kemper recounts a week of growing suspicion that Noel is having an affair. She repeatedly notices a distinct perfume on Noel after work, connects it to his increased absences and waning interest in sex over the past six months, and even stakes out his workplace for a day, concluding the affair must be with someone at work.

At home, Kemper finds a jewelry store receipt for an expensive necklace purchased with their credit card more than a week earlier, with no impending occasion that would explain a delayed gift to her. She takes this as confirmation that Noel bought the necklace for another woman.

Overcome with anger, Kemper moves to the kitchen to start dinner. She lights their unreliable stove and notices the strong odor of gas. She reflects that natural gas’s warning smell would alert most people to a leak, but Noel, who cannot smell, would be unaware and could inadvertently ignite an explosion.

Kemper connects the situation to a potential plan: if she left food for Noel to heat and ensured she had an alibi, an explosion might seriously injure or kill him. She briefly scripts what she would tell authorities, emphasizing Noel’s inability to smell gas and her own absence.

As her phone buzzes with an invitation from Kinsey to go out to dinner, Kemper initially ignores it but, after resolving on the plan, texts Kinsey back to confirm going out, thereby setting up the alibi.