Alec was always physically abusive to Isabelle in ways that, given their time period and social standing, could be excused as discipline. A tight hand on the back of her neck, an occasional slap, et cetera. However, the first time he actually full-on beat her was both more notable and less normalized to her, and was a major turning point in their relationship.

Alec had been grooming a teenage boy who worked with his father on the estate for some time, and Isabelle had seen the boy around and thought of him as a family friend. So when one day she, seven years old, found the boy tied up in Alec's car parked at the edge of the house, she acted on compassion without really thinking and set him free. He took off running, and Alec barely returned in time to shoot the boy before he escaped.

Alec then beat Isabelle, broke her legs, and dragged his still-living victim back to her just so he could kill her in front of him. Alec told her that the boy was already dead, that the type of people who are victims might as well be born dead, and that her actions had just accelerated the process. He told her her real crime was doing something that could have led to his arrest.

This laid the groundwork for many things in Isabelle's life. It was the first time she truly understood the reasons behind the fear people had of Alec, and it was the beginning of what would later be her Cotard's syndrome as she came to conceptualize abuse victims as the dead. The love that she had held for Alec before then became inextricably intertwined with fear, and in the emotional aftermath, where Alec barely spoke to her during her recovery, she developed a great fear of abandonment. This is also her physical disabling incident, so it haunts her the rest of her life.