We talked for 30, 40, sometimes 60 minutes about her garden, about the mystery novels she was reading, about the neighborhood cats she had named after Supreme Court justices.

She made me laugh in a way that Daniel increasingly did not.

When she was diagnosed eight months ago, I cried harder than Daniel did. He sat in the neurologist’s office with his hands on his knees and his face very still.

On the drive home, he said, “She’ll need to move in with us. I’m not putting her in a facility.”

I reached over and touched his hand and said, “Of course. Of course, she would come live with us. Of course, I would take care of her.”

He didn’t touch my hand back.

She moved in six weeks later. By then, the decline seemed to have accelerated. She confused names, lost words mid-sentence, sat for hours looking at things none of us could see.

The neurologist said this could happen. Rapid progression was not uncommon.

Daniel hired a part-time aide for weekday mornings. The rest of the time, Margaret was mine to care for.

I bathed her. I braided her silver hair the way she used to wear it in the photographs on her dresser. I read to her in the evenings, the mystery novels she’d loved, though she no longer seemed to follow the plots.

Sometimes she would look at me with an expression of such sharp, clear pain that I would have to look away.

I thought it was grief, the grief of a mind losing itself. I told myself that was the most human thing I had ever witnessed.

And I held her hand and I kept reading.

I did not understand that she was watching me.

The lavender tea was chamomile with a dried lavender stem she had apparently tucked into my spice cabinet sometime in the past week.

She steeped two mugs with the practiced ease of a woman in her own kitchen and set one in front of me without asking.

I sat down because my legs made the decision before my brain did.

“How long?”

I said it wasn’t a complete question.

She understood it anyway.

“Seven months and 11 days,” she said. “I was genuinely confused for the first three weeks after the diagnosis. The first thanks in advance did affect me. A small stroke, they said, very mild, but I recovered faster than any of them knew.”

She wrapped both hands around her mug.

“Daniel was at the follow-up appointment with me. He asked the doctor very casually, the way Daniel does everything, what the prognosis was for someone in my position. How long before the condition became, and I remember this word exactly, unmanageable.”

She paused.

“The doctor said it varied, two years, sometimes more. Daniel nodded and said, ‘Thank you,’ and drove me home and made me a sandwich.”

She looked at her tea.

“That night, I heard him on the phone. He was in his office with the door almost closed, but not quite, which I have always thought is the most careless thing a person can do. He was talking to a woman named Renee. He was telling her that his mother’s condition was more serious than expected and that things would be moving faster than they had planned.”

I felt something shift in my chest. Not shock. The shock was not quite available to me yet.

It was more like the feeling of a photograph slowly developing. Details emerging from blankness.

“Moving faster,” I repeated.

“I had my suspicions about Renee before the diagnosis. A receipt in his coat pocket, a name that appeared twice in his phone when he left it on the kitchen counter.”

She shook her head once, not with anger, but with the particular exhaustion of a woman who has been right about something terrible for a very long time.

“But suspicion is not evidence, and I had no way of getting evidence as his healthy, sharp, inconvenient mother who might make things difficult.”

“But as a woman who wasn’t all there,” I said slowly.

“I could be managed,” she said. “Moved in, cared for, contained, a problem solved, and in my diminished state, no one would take seriously anything I might say or do.”

She finally looked up from her tea and met my eyes.

“I chose to let them believe I was further gone than I was, Sarah. I chose it deliberately because I needed to understand the full shape of what my son was planning before I could do anything to stop it.”