While Kathy Humphries' son Karl was battling cancer, she took him for treatments to the pediatric oncology clinic at UNC Hospitals every two weeks.

After Karl died, at 13, in March 2007, Humphries kept going to the clinic every two weeks -- but with a different mission, one motivated by her son's love of reading and her need to do something positive in order not to be consumed by her grief.

"Karl was a big reader; books were an important escape for him when he had to go to the hospital so much," Humphries said. "When we started going, there was a woman who I think had cancer herself, who brought in books for the children. We enjoyed looking at them. But at some point, she didn't come anymore, and the books stopped.

"After Karl died, I wanted to do something for the clinic. I asked one of the physicians, Dr. Stuart Gold, 'What can I do?' He said, 'Karl loved to read. Why don't you start the book project back up?'"

So she did. She gathers children's books from far and wide, and once every two weeks she takes them to the clinic and puts them on the shelves. The kids in treatment are free to read them at the clinic or take them home, to keep.

One of the nurses dubbed Humphries the Book Fairy, and now Humphries wears wings when she goes to the clinic.

"A lot of people think, 'Oh, I could never go back there,'" she said. "But it helps me. I know what those families are going through, and I get so much out of the connection I have with the kids. Dr. Gold has become like a brother to me, and the nurses are the same ones that were there when we started going four years ago. They're like family."

Humphries has help. Her mother Josie and good friend Donna Lucier serve as assistant book fairies. She recently gained a new host of helpers: The Sophomore Class Council, a student club, at East Chapel Hill High School learned about her book project and threw itself into the task.

Led by club president Hannah Osborne, the students launched an expansive book drive. They set up a Facebook page, made fliers, solicited other students, had announcements read over the P.A. and sent notices home to parents.

"We got a lot of response," said Hannah, whose family is good friends with the Humphries. "A lot of students knew Karl from middle school. My sister Lydia was in the same grade, and she let me donate some of her books."

On Friday, during the lunch hour, Hannah and a dozen members of the club met Humphries, fully outfitted with wand and wings, and Lucier at the school. They filed into a storage room and emerged carrying cardboard boxes containing more than 1,000 books -- 1,078, to be precise. The students carried the boxes outside to load them.

"Karl was an avid reader," Hannah said. "It's important to keep his spirit alive."

The boxes filled the entire bed of Lucier's Dodge pickup truck.

"These kids see something that needs doing, and they take hold of it," said Vanessa Diggs, the faculty advisor to the Sophomore Class Council. "They did all the planning and all the work -- and it was a lot of work. They spent their lunch hours collecting, sorting, labeling. And they're already starting to plan for their junior year project. That tells you what kind of kids they are."

In a week or two, Humphries and Lucier will take the books to the clinic. She makes sure to include books for all ages, from board books to young adult novels. She makes a special effort to find books in Spanish, and she tries to be attentive to individual children's interests.

"Mrs. Humphries has added so much to the clinic experience it is hard to describe," said Gold, a professor in UNC's pediatric hemtology-oncology division. "She spends much of her day going around, collecting books from whomever she can, and brings them to the clinic for all to enjoy. These books are for keeps; kids with cancer and blood disorders, and their siblings get a book to take home.

"The first thing our kids do is go to the book shelf to see what is new and what they want to bring home. When it is a bad day, they get extra books."

Humphries will continue collecting books and taking them to the clinic. Seeing her books give children struggling with terrible illnesses a little bit of joy, she said, gives her even more.

"I know that if Karl could have gone in and seen this big selection of books," she said, "it would have made his day."

Anyone wishing to donate books for the pediatric oncology clinic can contact Humphries at her blog, http://karlsbooks.blogspot.com.