When she hung up, Peyton wondered if her mother was sick. She got the distinct feeling there was a secret of some sort her mother wasn’t telling her.

For some reason, her mind wandered to her brother, Andrew. He had died in Uganda, in 1991, while working on an AIDS awareness campaign for the WHO and Ugandan government. On a hot summer day in August, he was working in a village in the eastern part of the country, inside Mount Elgon National Park, when a forest fire consumed the village, killing Andrew, his Ugandan liaison, and all the residents. They had to verify his identity based on dental records and personal effects. At the funeral, on an overcast day in San Francisco, there was very little left to bury.

Peyton was thirteen then, and when the service was over, a woman with wavy blond hair walked over and introduced herself, speaking in an Australian accent. She had been a friend and colleague of Andrew, and Peyton sensed that perhaps they had been more. The woman reached into her pocket and brought out an item Peyton knew well: the silver pin Andrew had received a few years before at his medical school graduation—a gift from their father. The woman handed it to Peyton and said, “I believe your brother would have wanted you to have this.”

Peyton had turned it over in her hand, examining the serpent that wrapped around the staff. She was surprised that it wasn’t charred.

“I thought it burned.”

“I had it cleaned and refinished. I wanted you to have it in the same condition it was in when your brother carried it. All things can be repaired, Peyton. Some simply require more time than others.”

On that shadowy day in August, holding Andrew’s pin as the wind blew through her brown hair, Peyton knew for sure that she wanted to be a physician—and that she wanted to work in the field, helping people. Maybe it was because she wanted to continue Andrew’s work—he had been both her hero and her father figure—or maybe it was because she thought being an epidemiologist would somehow help her understand him or bring her closer to him. But she was certain being a doctor was what she wanted to do. And she had never regretted her career choice since. She knew the risks, and they were worth it to her.

She rose and set about getting ready for bed. She brushed her teeth, turned the shower on, and stripped off her tan service khakis. She sat naked on the closed toilet while she waited for the water to warm up. Her mind focused on her upcoming decision: Lucas Turner, the twenty-two-year-old American. Peyton wondered if he would be alive when she reached him. If so, what sort of shape would he be in? Would ZMapp be effective against the unknown viral hemorrhagic fever? Could it possibly make him sicker? And with or without ZMapp, would Lucas survive the trip to America? That was, if she followed the original plan she’d discussed with Elliott—the plan the director of the CDC had approved. That plan had been based on certain assumptions, and in the past hour, those assumptions had changed. The pathogen wasn’t Ebola.