Rebecca leads me down a narrow hallway until she finds the right door, and knocks. It opens only a crack, and Sergei peers out with wary eyes, warning we’d better not come in, since his baby brother is very sick. Rebecca lifts the basket of food so he can see it, and after a moment he pulls the door open wider and takes it, grateful.

Rebecca tells him she’s sorry about his brother, explaining that her mother sent bread, noodle kugel, fried fish, and vegetable soup, enough to last the family a few days. Sergei nods his thanks and lets us step just inside the doorway.

A wracking cough tears through the apartment, followed by a high, whistling whoop, as if someone can barely draw breath. Sergei’s mother hurries toward the back room without a word, and Sergei’s face goes tight with fear. The doctor has already come, he tells us, but the baby can still spread the sickness to anyone nearby.

When Sergei’s mother returns to the kitchen, dark shadows ring her eyes. She calls us kind but urges us to leave quickly, already easing the door shut. Rebecca asks if there is anything we can do to help before we go.

Sergei’s mother hesitates, then asks in broken English whether we might carry a message to her daughter, Edna, who works at the hat factory. It is an emergency, she explains. I nod, and Rebecca promises we will see it done.

Through the narrow gap, I watch Sergei’s mother scrub her hands with dark brown soap before she scratches out a hurried note and slips it through the crack for us to carry. She murmurs her thanks. Just before we go, I catch one last look at Sergei, pale and frightened, worried for his brother and, I suspect, for himself.

Downstairs at the front entry, a man in a dark suit is already nailing a sign to the outside of the door. “No school for you tomorrow,” he mutters, walking off. Rebecca and I step closer to read it together: WARNING. WHOOPING COUGH IN BUILDING.

Rebecca presses a hand to her mouth, smothering a small cry. Sergei’s baby brother has whooping cough, she murmurs, and reminds me that I came to New York partly to escape that very sickness. My stomach drops. I could catch it. Suddenly all I want is to get home, now.

I look down at the note still folded in my hand and realize, with a jolt, that even though Sergei’s mother scrubbed her hands clean, I might already carry the illness myself. Rebecca takes the note gently and unfolds it, reading the careful Yiddish script. It warns Edna of the sickness at home, she tells me, and begs her to stay with a friend until the danger has passed.

Rebecca seems to read the fear on my face. Rebecca says she’s sorry I got pulled into this, and I don’t have to come with her to the factory at all. Part of me wants to shake off my fear and stay close to her a little longer, but a part of me also wants to go home. Maybe Mom knows of some modern medicine that could prevent me from getting sick.