By this time, I think most Americans recognize Dr. Anthony Fauci as the face of the White House Coronavirus Task Force. Soon after the virus first hit American shores in 2020, he was there at President Trump’s side at nearly every press conference, eager to help us through one of the scariest—and deadliest—time periods in recent memory. Every day he approached the microphone to speak, it became increasingly evident that he was intelligent, knew his science, and that we could trust him to tell us the truth, even if it terrified us.

But what drove Fauci, 80, to pick up this torch when many of his colleagues have already retired? Where did he get enough confidence to be so brutally honest with the American people, even if it meant contradicting the president on national television? And who taught him to have such unmitigated compassion for his fellow man? All of these questions are answered in National Geographic’s new book, Fauci: Expect the Unexpected: Ten Lessons on Truth, Service, and the Way Forward.