In Amalia’s Tale, David Kertzer tells how in 1890 an illiterate Italian peasant woman—who contracted syphilis from wet-nursing a foundling—took on Bologna’s social and medical elite.

Both with Amalia’s Tale and your earlier The Kidnapping of Edgardo Mortara, you show a knack for finding stories that were sensational in their time but then forgotten.

This is such a dramatic phenomenon: women in large numbers who were getting infected with syphilis [from nursing foundlings]. The question was, was there a way to tell the story in a rich enough manner to make it come alive. [Unlike the Mortara kidnapping] this was a story that the authorities did everything possible to hush up, and the principal, as a peasant, was powerless. I was fortunate because, as I dug further and further, I found a treasure trove of materials in an unexpected way for such an obscure person. One thing I discovered while doing the Mortara book was how vital and rich court records can be in providing insight into the powerless and illiterate people of the past.

While reading Amalia’s Tale, feelings shift from sympathy for Amalia into seeing the foundling home’s dilemma: wet-nursing, with all its risks, was the only way to feed the infants.

[A story of good vs. evil] would make, first of all, a lousy book, but it also would make lousy history. What makes it so powerful is not how an illiterate woman is victimized by elite men. What’s powerful is what makes you think. Just when you’re rooting for one, you realize this may be going in a very bad direction. And these people who are cast as villains—they themselves thought they were working for the greater good. This makes it a less comfortable narrative, but that complexity makes it more interesting and also more historically valuable.

At the end, you talk about your methodology for writing a book that’s historically valid and also appeals to a popular audience.

This book begins when Amalia comes to see her lawyer. For a book like this you need to set up that scene, to provide drama. But there’s a lot we can never know about a scene like that. What was he wearing, what did his office look like? I did a lot of research on the clothing of the bourgeoisie and found paintings and photographs of law offices in that era. As a younger scholar, it would be more difficult for me to write a book like that. At this stage in my career [Kertzer is provost of Brown University], I’m not so worried about what people think of the quality of my scholarship.