As the fog cleared and the faint light of the stars and a sliver of moon illuminated the shore, Arthur Stuart realized that the man sitting crosslegged in the shallow water was Alvin.

At once Arthur strode forward, but said nothing, because Alvin seemed to be concentrating. Arthur came up beside him and saw that Alvin held a knife in his hand, with the tip of the blade under the water. He was slicing into the soft skin on the side of his left heel, under the place where the leg bone joined on.

Blood began to flow out in a slow trickle into the water.

Almost by habit now, Arthur Stuart tracked the blood in the water, feeling its dissipation. But then it stopped dissolving, and instead began to form a rigid structure, gathering water around a delicate latticework, thickening and hardening the water into something not at all like ice, and very much like thin, delicate glass.

The area of hardened water extended to about six feet on either side of Alvin, then narrowed gradually as it extended out over the lake. When it narrowed to about as wide as Alvin's arms could reach on both sides, it stopped narrowing and went on and on, straight north. Arthur could sense it moving forward. But he could also sec that it was all connected to Alvin's living blood, still flowing out into the water and thrusting the lacy inner structure of this crystal road farther and farther out. The bridge was growing from the base, not the tip.

"Can you see it, Arthur Stuart?" whispered Alvin.

"Yes."

"And on the other end, do you think you can anchor it there and hold it firm?"

"I can try."

"It's taking more blood than I hoped," said Alvin, "but less than I feared. I'm not sure I'll know when it's long enough. I have to concentrate on what I'm doing here. So I need you to lead the way across, because you can see it. And when you get to the end, anchor it and stop it from growing. I'll feel it at this end. I'll know that you're doing it, and I'll know when it's done."

"Now?" said Arthur Stuart.

"If we're going to get all these people to walk across in one night, I think now's a good time to start."

Arthur Stuart turned around and beckoned to Moose and Squirrel. They didn't see him. So he called out, but not loudly. "Papa Moose! Mama Squirrel! Can you bring the children?"

With Papa Moose leaning on Mama Squirrel and one of the older boys, they came down to the water's edge. When they arrived, Arthur Stuart stepped out onto the crystal.

To the others it seemed that he stood on water. They gasped, and one of the children began to cry.

"Come closer," said Arthur Stuart. "See? It's smooth where it's safe to walk. It's not water any more. It's crystal, and you can walk on it. But stay to the middle. Hold hands, stay together. If someone falls in, pull him back up. It's strong enough to hold you, see?"

Arthur looked straight down into the crystal as he stomped his foot a couple of times.

What he saw there made him freeze.

It was his mother, flying, a newborn baby strapped in front of her. Flying over the trees, heading north, to freedom.

And suddenly she could fly no farther. Exhausted, she tumbled to the earth and lay there weeping. She would kill the baby now, Arthur Stuart realized. Rather than let it be taken back into slavery, she'd kill the baby and herself.

"No," he murmured.

"Arthur Stuart," said Alvin sharply. "Don't look down into the crystal."

Arthur tore himself away and was surprised to find Moose and Squirrel and their family all watching him, wide-eyed.

"Nobody look down into the bridge," said Arthur Stuart. "You'll think you're seeing things, but they're not really there. It's not a thing to look at, it's a thing to walk on."

"I can't see the edges," said Mama Squirrel. "The children can't swim."

"They won't have to," said Arthur Stuart. "Let's get the little ones in between the older ones. Everybody hold hands."

"The youngest can't walk so far," said Papa Moose.

Someone pushed her way through the family to the water's edge. La Tia. "Don't you fret about that. Got plenty of strong arms here to carry them as can't walk." She called out several names, and strong young men and women stepped forward, most of them black, but some French or of other European nations. "It's all right, babies," La Tia said to the children. "You let these big folk carry you, you be all right. You tell them be happy," she said to Mama Squirrel.

"It's all right," said Squirrel. "These are our friends now, they're going to take us out across this bridge Alvin's done made for us."

Some of the children whimpered and a few cried outright, but they hung on all the same, doing their best to obey despite their fear. Arthur Stuart walked farther out onto the bridge, taking care to stay right in the middle. The worst thing he could do would be to stumble off the edge. They'd all be terrified then. "Come to me," he said. "We have to move quick, once we get started."

"I stay right here," said La Tia, "I keep it all moving, I make everybody help each other. You go, you. We follow."

Arthur turned around and walked a good twenty paces out onto the bridge. Then he stopped and turned around. Several of the older children were following him tentatively. He strode back to them and took the leading child by the hand. "All hold hands," he said. "Stay right in line. It's a long walk, but you can do it."

"Listen to the music," said Alvin. "Listen to the music of the water and the sky, all the life around you. The greensong will carry you forward."

Arthur Stuart knew the greensong well, though he could never find it on his own. As soon as Alvin spoke of it, though, he became aware of it, as if it had always been there, and he'd just not bothered to notice it before. He stepped on out, holding the hand of the child behind him, and set a pace that he thought everyone would be able to keep to.

In the darkness, he couldn't see the bridge stretching out before him-his eyes told him only that he was walking out into the middle of a trackless lake. But his doodlebug felt the bridge as clear as day, reaching on and on, out and out, and he walked with confidence.

At first he couldn't stop his mind from fretting about all that could go wrong. Somebody falling off. Losing the way somehow. Getting to the end of the bridge and finding that it didn't quite reach the other shore. Or having the bridge get softer and wetter the farther it got from Alvin. Or the bridge bending in on itself, making a spiral that led nowhere. All kinds of imaginable disasters.

But the rhythm of the step, step, step and the sound of the lapping water and the calls of birds began to still that relentless fretting. It was the familiar rhythm of the greensong. He let it come over him like a trance. His legs began to move, it seemed, of themselves, so he no longer thought about walking or even moving, he simply flowed forward as if he were a part of the bridge, as if he himself were a breeze on the night air. The bridge was alive under him. The bridge was part of Alvin, he understood now. It was as if Alvin's hands bore him up, as if the water and wind drew him along.

He only sometimes noticed that he himself was singing. Not just humming, but singing aloud, a strange song that he had always known but had never noticed before. The child behind him picked up the melody and murmured it along with him, and the child behind her, until Arthur Stuart could hear that many voices carried the song. No one was crying or whimpering now. He could hear adult voices farther back. But all of them were faint, only threads amid the fabric of the great wide song that Arthur heard from the wind and the waves and the fish under the water and the birds in the sky and from animals waiting for them on the other side and from all the people on the bridge, a half mile of them, a mile of them.