For almost five weeks, Farmer spent much of her day with the boy, rubbing his stomach to ease his acute pain, or reading to him -- first in English, later in Khmer, the Cambodian language she was studying.
Most of the time, the boy was in too much pain to respond, she says. But on one of his better days, she showed him her camera, a hefty Canon 5D Digital.
"At first, he was scared. He didn't know what it was. I turned it around, took a picture of myself and showed him the image. He recognized my face. He smiled -- his first smile since I'd known him. I'll never forget it," she says.
She hung the camera around the boy's neck, and he started taking pictures, his pain forgotten for a brief while. It was art therapy in action.
A few days later, his bed was empty.
"I thought he'd died," says Farmer. "But a nurse told me his mother came in the middle of the night and took him away."
His disappearance was one of the experiences she shared, along with her photographs, during her visit to DBCC.
The pictures were "beautiful as well as emotional," says student Laura Wong, 21. "When she was talking to us, I was aware of her pain, but also her sense of purpose. I would love to do something similar -- to travel, to help get the word out about people in need. It's what we have to do if we're going to survive in this world."
During the last two months of her stay, Farmer immersed herself in the hospital's art-therapy program, spending time drawing, painting and doing origami with the children.
There were so few coloring books, she says, "We had to trace pictures for the kids to color so they didn't use up the books."
Days before her departure, she bought disposable cameras for her charges, gave them 24 hours to document their lives in pictures, then mounted an exhibition showcasing their efforts.
"Seeing their faces when they recognized their pictures on the wall was just amazing," she says.
One of the first adults to view the photos was former President Bill Clinton, who happened to be touring the hospital.
"He was very approachable and personable," says Farmer. "He talked to the staff and the children, and asked a lot of questions about the AIDS outreach program."
Spending time with children suffering from AIDS and other serious conditions was emotionally draining, says Farmer. Watching them die was devastating. Even more difficult was watching the parents watch their children die.