Soon Debra and John were quietly looking for a place together. It had to do with vigilance and quick reflexes and the will to fight.They found a ,500-a-month house on the boardwalk on Balboa Island in Newport Beach. “The world ends,” she would say, “and those who are fit to survive will survive.” She was as nonconfrontational as her sister Jacquelyn was assertive.

Terra discovered the truth the day before Thanksgiving, when she opened a closet and found a nursing certificate bearing John’s name. ” Terra left, badly shaken, with the sickening feeling that her mother was choosing John over her.

Her mom said she was getting his certificates framed, but Terra knew, and she did something uncharacteristic. He had an explanation for why he had a nursing degree but called himself a doctor. When Jacquelyn showed up, John asked for a private word with her. He acted like a kid himself, vulnerable and sweet, and single-mindedly besotted with her.

Her four kids were grown, she ran a flourishing interior design firm, and she was looking for a man to share her success with.

Her date was 55, 6 feet 2, with hard-jawed good looks and a gym-sculpted frame.

High black Gucci heels, designer jeans, Chanel bag.

At 59, married and divorced four times, she had begun to worry that she was too old for another chance at love.

She felt protective of her mom and wondered why a guy who sounded as good as John would still be single. Why had no one seen John’s houses in Newport Beach and Palm Springs?

Her skepticism only deepened when she and Jimmy drove out to Southern California and met him. As he helped Debra move into her new house, he huffed and strained and wrestled her queen mattress down the stairs single-handedly, a show of ludicrous machismo. She thought maybe they were picking up on her own unease. Why did he seem to spend all day playing “Call of Duty” on the 70-inch plasma TV her mom had bought?

She thought they’d find something bad to say about anyone she dated. Debra wasn’t about to tell her kids that John would be moving in with her. At 23, Terra watched and rewatched every episode of “The Walking Dead.” She spoke of the series less as entertainment than as a primer on how to survive apocalyptic calamity.

Her friends sometimes joked about her being a “bad picker.” Where other people saw red flags, she saw a parade. She knew what they’d say — that she was moving too fast, acting with her heart, repeating old mistakes. She made careful note of why some characters lived and others perished.

He looked a little weathered, and he dressed lazily — shorts and an ill-matching preppy shirt — but he might have once been an All-American quarterback on a trading card. He had thick dark hair and a warm, friendly smile that invited trust.