The results were dramatic. Nine lines quickly diverged from the point of impact. There were humps at the heads of the lines and shallow depressions behind them that quickly filled in with sand. The humps moved as swiftly as cartoon gophers under a suburban lawn. In a few seconds there was no sign they had been there.

Cirocco had risen to her knees when the missile hit the sand. Now she slumped back to a sitting position.

"What do you want to do?" she asked. "Head on west to Thea?"

"No. I'm sure you recall who wanted to do this and who wanted to stay home."

"And drink," Cirocco added.

Gaby ignored it. "I'd look silly advising you to skip Tethys after all the time I spent convincing you to come here at all. Let's see what we can do."

Cirocco sighed. "Whatever you say. But look out, everybody. I want the humans watching the air. Titanides, keep an eye on the ground. You can usually see a spurt of sand before the wraiths come out onto the surface."

When Robin was nine, she read a book which had made a lasting impression on her. It was about an old fisherwoman who, alone in a small boat, hooked a huge fish and battled it for days, through storms and high seas. It was not so much the struggle with the fish that had frightened her. It was the evocation of the sea: deep, cold, dark, and unforgiving.

She thought it odd that she had not recalled the book while crossing Nox or Twilight. It seemed even stranger that she would think of it now, in broad daylight, crossing the arid desert. Yet the sand was a sea. It undulated in broad waves. In the distance, some atmospheric effect made it shimmer like glass. And beneath its surface were monsters more terrible than the old woman's fish.

"I just thought of something," Cirocco said. She was riding alone on Hornpipe, followed by Robin on Hautbois and Chris and Gaby on Valiha. "We should have gone north to the road, then back west to the cable. It would have been a shorter distance over dry sand."

Robin recalled the map Cirocco had drawn. "But we would have spent more time covering flat ground," she said.

"That's true. But somehow I'm more worried about wraiths than buzz bombs."

Robin did not say it, but she was, too. Though she was supposed to be scanning the sky, her eyes were constantly drawn to Hautbois's hooves as they kicked up the loose grains of sand. She could not understand how the Titanide could bear it. Her own toes curled in her boots in sympathetic horror. Any moment now some hideous mouth would appear and engulf the Titanide's forelegs. Except Cirocco had said the wraiths had no mouths, eating by directly ingesting through their crystalline carapaces. They did not even have faces...

"Do you want to go back and do that?" Gaby called out.

"I don't think so. We're about halfway there."

"Yeah, but we know there aren't any wraiths back-"

As soon as Gaby stopped shouting, Robin's heightened awareness told her that something was wrong. She had a pretty good idea of what Gaby must have seen, and it took only a few seconds of scanning the near side of the five-meter dune behind them to find the telltale grooves in the sand, deep in front, trailing away like the tail of a comet. She saw a dozen of them, then realized that was only one of five or six groups.

There was no need to raise an alarm. Robin saw Cirocco standing on Hornpipe, facing backward. Valiha increased her pace until she was beside Hautbois and Robin. Gaby was passing bladderfruit to Chris and Valiha.

"Hand me one of those," Hautbois said, and Robin did, feeling the Titanide increase her pace. For the first time on a Titanide she felt some of the bouncing associated with horseback riding.

"Hold your fire for now," Gaby said. "That's as fast as they can move, and we're staying ahead of them easily."

"That's easy for you to say," Valiha said. Her mottled yellow skin glistened with foamy sweat.

"It's time to switch," Hautbois said. "Valiha, give me Gaby for a while. Robin, you move to the front." Robin did as she was told, noting that she would be sandwiched between Hautbois and Gaby and, though it was painful to admit it, not objecting at all. The unseen wraiths frightened her more than anything she had encountered in Gaea.

"Just a second," Gaby said. Ignoring her own order, she turned around and lobbed a bladderfruit into the path of one approaching group of wraiths. They sensed it while still fifty meters away. Some swung wide to avoid the poisonous area, while others vanished entirely.

"That's got them," Gaby said with satisfaction as she landed on Hautbois's back. She settled in behind Robin. "The ones that disappeared went deeper in the sand, but that slows them down a lot. They can only move at top speed near the surface, where the sand is looser." Robin looked back again and saw that the ones which had swung wide were only now resuming the chase, far behind the vanguard.

"How about it, friends?" Cirocco said, addressing the Titanides. "Can you keep up this pace until we reach the cable?"

"It shouldn't be any problem," Hornpipe assured her.

"Then we're all right," Gaby said. "Rocky, you'd better throw a small bomb ahead of us every few minutes. That ought to scatter any ambushes."

"Will do. Robin, Chris, stop looking at the ground!"

Robin forced herself to look at the sky, still painfully clear and fortunately empty of buzz bombs. It was one of the hardest things she had ever done. It could not have been harder if her own feet were touching the hated sea of sand; like a backseat driver reaching for an imaginary brake, she found herself lifting her feet in an effort to make Hautbois step more carefully.

The group had crested a dune and was starting down the other side when Cirocco called out a warning.

"Hard right, people. Hang on!"

Robin put her arms around Hautbois's trunk as the Titanide dug her hooves into the sand, heeling over almost forty-five degrees as she turned. The ride was definitely getting bumpier as Hautbois began to tire. Robin caught a glimpse of a commotion at the foot of the dune, saw several of the telltale trails as wraiths fled from the bladderfuit that had suddenly exploded in their midst. A stream of water came from behind her, angled left, sizzled when it hit. There was a fountain of sand. For a moment a supple insubstantial tentacle writhed in the air. Where the water touched it, the thing hissed and shed glass scales that turned slowly in the low gravity. Robin freed one hand and took the butt of her water pistol in the other, peering around Hautbois's broad shoulder. She squeezed the trigger and sprayed what turned out to be a harmless patch of desert.

"Save it," Gaby cautioned. Robin nodded quickly, mortified that the gun was shaking in her hand. She hoped Gaby couldn't see it. Gaby's voice was calm and controlled and made Robin feel ten years old.

The Titanides had made a wide circle around the nest of wraiths Cirocco had exposed; now they were back on course for the Tethys cable. Robin remembered to look up at the sky, saw nothing, looked back at the sand, once more forced herself to look up. She did that for an hour while the cable base grew no closer. Finally she asked Gaby how long they had been running.

"About ten minutes," she said, and looked behind them again. When she turned back, she was frowning. On the crest of a dune five or six hundred meters to the rear Robin thought she saw a wraith track. It paralleled the imprints of the Titanides' hooves.

"They're still back there, Rocky."

The Wizard looked, frowned, then shrugged.

"So? They can't catch us if we keep going."

"I know. They must know that, too. So why do they keep coming?"

Cirocco frowned again, and Robin didn't like that. Eventually Gaby reported she could no longer see the pursuers. Though the Titanides were tired, they agreed not to slacken their pace until the cable was reached.