Their first reaction was: No. No! No!!! When an oncologist from Cincinnati Children's Hospital called documentary filmmakers Julia Reichert and Steven Bognar to ask if they'd like to make a movie about children with cancer, the couple had just seen their teenage daughter through a siege of Hodgkin's lymphoma. "We had a feeling in our gut, we can't walk down those hallways again," remembers Bognar. But after 15 minutes, they changed their minds. "Something bubbled up in us and said, 'Are you crazy? This is a chance to tell the story of what we and all the families we met have been through.'" That was eight years ago. In January, they brought their four-hour film A Lion in the House to the Sundance Festival--the same month Reichert herself was diagnosed with a rare strain of lymphoma. PBS will air the movie on the Independent Lens series, on June 21 and 22.

Where did the title come from?

Reichert: It's from a quote we heard early on in making the film, which is from Isak Dinesen, author of Out of Africa: "You know you are truly alive when you are living among lions." The metaphor [could be] that cancer was a lion that could kill you at any moment, a terribly scary beast in the house. But the year I spent worrying and watching my daughter so closely to make sure she was going to be OK, I felt like a mother lion taking care of my child.

Aren't the kids like lions, too?

Reichert: I feel like the kids have the courage of lions.

Plus, a film called "Children with Cancer" probably would discourage viewers.

Reichert: We thought a mysterious title was good.

Do you worry no one will want to watch a four-hour film that closely follows five kids with cancer, some of whom die?

Reichert: People tell us that every day. I tell people, "Watch the first 30, 45 minutes. If you want to leave you can, but just give it a chance because it's not what you expect."

That's true. The kids are so full of joy and playfulness. They mess with their docs, they ride bikes, they have a good time despite cancer. There is a sense that somehow life goes on.

Bognar: You see how people recover and reclaim their lives, regardless of what happens. How people keep going is a huge part of the film.

When death is imminent, do you think children realize they are about to die?

Reichert: The widespread belief among nurses--who spend much more time with kids than doctors do--is that children do understand when their life is about to end. They're not afraid of it, but they're afraid of disappointing their parents, of making their parents cry. They'll confide in a nurse, "I know I'm going to die. I know I'm going to go to heaven. But don't tell my mommy; she'll get upset."

Julia, what have you learned from the kids that helps in your own fight with cancer?