It was exactly what you say: I was looking for a rabbit hole sort of thing, but I wanted it to be in contemporary terms. I was thinking about what was a common experience for children that was a transition point where something changes. It seemed to me that almost every kid has been in a car going through a tollbooth.

Not in California. That baffled me as a child.

You didn't have tollbooths?

No, it was all freeways. Although that wasn't any more baffling than the treacle well in "Alice in Wonderland." I spent a lot of time wondering what treacle was.

Now that they're starting to get rid of tollbooths, a lot of kids may be in your position with my book. But having been brought up in the East, it was something I was very familiar with and it seemed like a perfect, contemporary way for a kid to go from one world to another one.

An example of the deft writing in the book is how the magical things aren't overly described or explained. There's a scene in the Fortress of the Soundkeeper in which the Soundkeeper pulls out an envelope and tells Milo that the exact tune George Washington whistled as he crossed the Delaware is inside it. Then you write, very simply, "Milo peered into the envelope and, sure enough, that's exactly what was in it." And perhaps first among the many other things that are left unexplained in the book is exactly who sent Milo the tollbooth. Do you have an idea of who it was?

That question gets asked more frequently in the mail I get than almost any other question. I had a phone call from someone recently who wouldn't let me off unless I told him where the tollbooth came from. And frankly, I don't know where the tollbooth came from. It was just there. We conjure things in our own minds to fulfill the requirements we have. Obviously there was something inside Milo that was trying to get him out of that ennui so that he could understand the real joys of life, which are learning and being involved in things. So even if I did know, I wouldn't tell anybody where that tollbooth came from.

While you were writing "The Phantom Tollbooth," were there any scenes that surprised you as you wrote them, or made you wonder, "Where did that come from?"

What jumps to my mind is the scene of Milo conducting the dawn. And that's interesting because when the manuscript was turned in, the editor didn't like that and wanted to cut it. He was a wonderful editor, really terrific, and we argued about it. A lot of what he'd said I acted on, but finally with this one, he said, "Well, it's your book." So we kept it in.

I don't know why it happened, but it was as you described it. As I was writing that scene, a couple of times I had to catch my breath because I didn't know where I was going with it. It just began to happen.

It's one of my favorite scenes in the book. The conductor who conducts all the colors in the world, the Great Chromo, asks Milo to watch his orchestra during the night while he gets some rest. Milo decides to try his hand at conducting the sunrise, and the result is pretty disastrous, with colors going all wrong and the sun rising and setting seven times, very quickly. But Chromo sleeps through this and you write, "To this day no one knows of the lost week but the few people who happened to be awake at 5:23 on that very strange morning."

One of the ways I thought about ending that scene was with Chromo getting up and saying, "Oh, I had such a wonderful night's sleep. I feel like I slept for a week!"

Let's talk about some of your other books, which some fans of "The Phantom Tollbooth" may not know about, even though they've been quite successful. "The Dot and the Line," which has just been republished, is "a romance in lower mathematics" as you call it, in which a straight line is in love with a dot who has inexplicably attached herself to a good-for-nothing squiggle.

The story came very quickly. It struck me as funny, this whole triangle. The squiggle is an absolutely disreputable character who treats women badly, yet they flock to him. I knew several people who were that way. I was more like the line. I was never the romantic lead in any of these things.

I had a terrible time thinking of how to illustrate it. One illustrator, an old friend, said, "You have to do it. It's your book." Once I realized that, I had a lot of fun doing it. When I finally handed it in, I had a moment when I thought, "Nobody's going to think this is funny at all. It's my own little thing," but it's been in print for about 38 years, and now it's come out again with a lot of interest. It amazes me.

Maya Angelou reads from "The Heart of a Woman"