"I thought you were going to follow me," Cirocco shouted, and laughed again. "I thought you were All-Coven Girl Champeen, or something."

"Oh, yeah?"

Nova hauled on her lines with both hands and swept so close in front of Cirocco she could hear her startled gasp. Downward she plunged, faster and faster, swinging from side to side and building momentum until, with a hard jerk, she swooped up and around and poised for a moment, upside-down, the wing collapsing beneath her. She tumbled, expertly avoiding entanglement with the loose lines, was jerked to a stop amid the sharp cracking sound of the wing catching air, and came out in a glide, neat and sweet as ever it had been done in competition. She could see, in memory, the string of 10's flashing on the judges' scoreboards.

Cirocco eased in beside her, just far enough away to keep their wings out of trouble, and regarded her with a sour look which she couldn't maintain. She burst out laughing again.

"I yield to the better woman," Cirocco said. "You gave me a fright there, young lady."

"You scared me," Nova protested.

"Yeah, I guess I would have. So I probably shouldn't have done it."

"I didn't mind."

"Nova, I know I seem like a very cold, very sour old bitch. Lately I can't afford much time to have fun. And I know I'm six times your age, and I know you've heard the tragic story of my life ... but you know what? Adding it all up, the good and the bad, I've had a great time. The last thirty years have been hard, and they're about to get harder. But I wouldn't have liked any other life. The awful thing is ... well, like now. When I want to cut up, it just seems out of character. That saddens me."

The last thirty years, Nova thought.

It was a long glide. They amused themselves with some more tricks, though nothing as extreme as the loops. And all the time, Whistlestop continued to grow larger beneath them.

Almost a century ago, when Cirocco and her crew had first seen him, Whistlestop had been just over one kilometer from nose to tail. The Hindenburg, the largest airship ever built on Earth, had been slightly less than a quarter the size of Whistlestop.

Since then, he had grown considerably.

Now he was two kilometers long. With the proportionate increase in his other dimensions, he was eight times as large as he had been. He contained half a billion cubic feet of hydrogen.

"Nobody knows why he grew so much," Cirocco told Nova as they made ready for landing on the broad back. "Blimps don't usually grow so quickly. I know he's about sixty thousand years old. His contemporaries only seem to grow a few inches every year. I know that Old Scout, who is at least twenty thousand years older than Whistlestop, is only about a kilometer and a half long."

There was more, and Nova listened to it all, but mere words could never do justice to Whistlestop. He had to be seen to be believed. She had thought making a landing on the back of a blimp would be a hazardous thing. It was going to be about as difficult as a mosquito landing on an elephant.

She touched down lightly, ran a few steps as she expertly reefed her chute, and was about to pull it in for folding when Cirocco touched her shoulder.

"Cut it loose," she said. "We'll get down another way."

"I don't have a knife," Nova said.

Cirocco looked surprised, then shook her head.

"I'm getting senile, I guess," she said, looking Nova up and down. Nova couldn't figure out what the problem was. Cirocco severed Nova's lines with a white-bladed knife. When she got a close look at it, Nova realized it was made of sharpened bone, intricately carved in the Titanide manner.

"You wearing anything under those clothes?" Cirocco asked.

"Just cotton shorts," Nova said.

"It's metal I'm looking for. It's not only impolite but extremely dangerous to take anything metal onto a blimp. Anything that can spark."

There were metal grommets on Nova's bootlaces, but after a close look Cirocco pronounced them acceptable. Nova was relieved, they had been a gift from Virginal.

Then Cirocco knelt and started feeling the tough hide of the blimp. Nova followed her. She knew she should be asking questions, but, despite the glimpse of a fun-loving Wizard she had had on the way down, her predominant reaction to Cirocco was awe, and her response was obedience.

She looked around. It might as well have been a flat, silvery saucer. She knew it curved downward, but she could have walked a long distance in any direction before it became a problem.

At last Cirocco seemed to have found her spot. She pressed the point of the bone knife to the blimp's skin and made a small hole. Nova watched her hold her hand over the puncture. She heard a hissing sound that soon subsided. Cirocco seemed satisfied, and, to Nova's amazement, she used the knife to make a large X in the blimp's hide. She pushed the flaps down into the hole, and the two of them looked into the incision.

It led down into blackness. On all sides of the narrow chimney the walls bulged inward, restrained by what looked like fishnet. Nova realized they were gasbags, and Cirocco had located a space between them.

"What if you'd punctured the bag?" Nova asked.

"Whistlestop has over a thousand gasbags. Three hundred of them could be holed at once and he'd still be okay. And if my first puncture had hit a bag, it would have healed in about ten seconds." She lowered her legs into the hole, found a footing, and grinned up at Nova.

"You folow me, okay?"

"He doesn't mind?"

"This hole will heal in five minutes. He won't even notice it, I promise."

Nova was dubious, but it had no effect on her willingness to follow. As soon as the Wizard's head was gone she stepped down, slipped, then grabbed onto some of the netting around her.

"Push the flaps back up," Cirocco called out, from below. "That'll make it heal faster."

Nova did as she was told, and it got darker inside the blimp.

"Now, just climb down. You'll see some things, but don't worry about them. There's nothing in here that can hurt you."

They descended a long time. At first it seemed utterly dark, then Nova's eyes adjusted and she could see a little.

It was easier to hold with her fingers, but it was tiring. From time to time her feet would find a larger cable she could perch on, but usually there was just the fine netting. Only the low gravity saved her.

After ten minutes there was a light below her. She stopped, and saw Cirocco taking a small, glowing orange globe from her pack. She handed it to Nova, and tied another around one of her wrists. It was a kind of bioluminescence, and it was sufficient to see by.

It was better at first. She could see where to put her hands and feet. Then, oddly, it began to make her feel more claustrophobic. It was like a nightmare where the walls were closing in on you, but it was real. The walls did bulge.

Then she thought about what she was doing. The things she grabbed and held were not ropes, not nets; they were the living muscles of a gargantuan being. She could feel them moving when she pulled on them. They were dry, thank the Great Mother and all her little demons, but it was still creepy.

They went by side passages. Some were no wider than her arm, but a few were big enough to walk in. Far away in the larger ones she could see eyes glittering.

"Cherubim," Cirocco said, after the first sighting. "They're the same relation to Angels as monkeys are to us. They nest in the greater blimps."

There were other denizens of the sky leviathan. Little things like mice kept skittering over her feet, and once Cirocco paused while something bigger scuttled out of her way. Nova never saw it, and didn't mind that at all.

"You're sure he doesn't mind us in here?" she asked, at one point.

"The more the merrier," Cirocco said. "If he didn't want us here we'd know it by now. All he has to do is seal this passage and flood it with hydrogen. Don't sweat it, Nova. Blimps have their own internal ecology. There's a hundred animals that can't live anywhere else. And they take on transient passengers all the time."