Wen had written the op-ed in the wee hours of the morning after having worked 14 hours the day before. Aside from two tiny typos, it was flawless. (It was later published in The Washington Post.)

Since January, Wen has been running one of America’s oldest and most experimental health departments, in one of the poorest cities in the country. Throughout my day with her, I learned a lot about how racial disparities and poverty pry an immense gap in the health outcomes of a community. I heard about some unusual strategies—like using ex-cons to patrol neighborhoods and break up fights—that public-health experts are employing in order to address those problems.

Also, I learned that I cannot keep up with Dr. Leana Wen.

After we looked at the op-ed, it was time for the meeting. The topic of discussion was, broadly, why poor kids are so much more likely than rich kids to get asthma. In some local schools, one person said, half of kindergarteners have asthma. How could we expect kids to get better when roaches roam their bedroom walls? Or when their parents didn’t get paid before the inhaler ran out? Certain interventions—more health workers, better pillow covers—have proven to work, participants noted, but there’s not enough money to fund them.

Wen interrupted with a more inspirational note: “There is a tide of change that’s been coming in the past few years. I’m curious as to what you think the opportunities might be, not only with the [Affordable Care Act], but also with global budgeting affecting our hospitals in Maryland. Might there be opportunities there in order to use innovations that will keep people out of hospitals?” (Last year, Maryland became the talk of the health-policy world when it decided it would cap how much hospitals can spend—in effect rewarding hospitals for keeping people out of them.)

About halfway through the conversation, Wen rose abruptly, thanked everyone, and said she had to be off. Because of the recent riots, she and the city’s other agency heads had an emergency cabinet meeting.

Outside, she turned to me with a slight frown. “Unfortunately, I often don’t get to see all of any one meeting,” she said.

She phoned Shirli Tay, her assistant.

“Shirli, I need your help. Can you send Olga the call-in details? And where’s Michael, because I need him to review that op-ed, like, now. Like, urgent.” But she ended sweetly: “Cool, see you soon, bye.”

Throughout the day, I would learn that interacting with Wen is a bit like swallowing a lit firecracker. Except instead of killing you, her force makes you feel smarter and healthier.

Wen told me to call into her scheduling meeting at 8:30, but also to drive to the offices of the city public health department by 9. She rattled off the address and I started repeating it in my head so I wouldn’t forget it before I could get back to my car and punch it into Waze. I’m an atrocious driver and even worse when I’m on a conference call, but I figured I’d give it my all.