As a nurse, Zoe used to rely on her mother-in-law, Denise, to care for her son, Leo. But when the little boy becomes visibly agitated by his grandmother’s presence, Zoe has to question the elderly woman’s actions, only to discover she has a hidden agenda.

I’d always thought my mother-in-law, Denise, was a bit overbearing, but I attributed it to her simply protecting my son, her only grandson, Leo.

She was one of those women who carried herself with a certain authority that made you straighten your back and reconsider your words. This was accentuated when Jeremy, her husband, passed away a few years ago, allowing Denise to resume her role as head librarian at the local library.

“Why wouldn’t I?” she asked my husband, Andrew, one day. “I have time now, so there’s no need to have only my part-time role there. And I can also hold my book club meetings at the library.”

“Okay, Mom,” Andrew said. “Do whatever you want.”

She wasn’t exactly mean, but Denise had a way of making you feel small without even trying. Still, she lived two roads away and was always willing to babysit Leo when I had a shift at the hospital, and given Andrew’s unpredictable schedule at the law firm, she often had to step in.

“That’s what grandmas are for, right, Zoe?” she’d say whenever I asked her to come over.

And even though her mood could change without warning, she was trustworthy and never complained once.