Are you pregnant?” Sabrina asked me.

“No,” I said. I was leaning against the plastic divider of the nurse’s station at the clinic where I worked part time interviewing patients for a psychologist’s study of depression. Normally my contact with Sabrina, or with any of the nurses, was brief, involving the whereabouts of patients who had screened positive for depressive symptoms.

That morning, though, I had fainted on the train on my way to work. In the past, my occasional fainting spells — officially known as vasovagal syncope — had been precipitated by specific sources of pain: if I had a bad stomachache, say, or twisted my neck oddly.

I had grown accustomed to predicting these episodes just before they began. But that morning on the train it occurred at random, when I was otherwise feeling fine, which had left me sufficiently rattled that I sought out Sabrina in the nurse’s station.

Sabrina was my favorite nurse. She wore cat-eye glasses with plastic floral-print frames and scrub tops long and belted, like ’80s dresses culled from a vintage clothing shop. Sometimes I’d catch her on “kitchen duty,” as she called it, emptying basins of bloodied instruments on Wednesday mornings.