It's not enough to have power, Alvin. You have to have the will to use it.

Street after street, the fog crept through the city, dimming the light of the setting sun and hiding passersby.

Slaves felt the cool clammy fog pass around them, or looked out windows and watched as buildings across the street disappeared, and they thought, Today we cross over Jordan to the promised land.

In Frenchtown the children and grandchildren of the founders of this place, whose city had been stolen from them, looked out of their shanties and thought, You can't keep us here no more, Conquistadores. You can take our city, but that's only land. You can't hold onto us when we've a mind to go.

In Swamptown, the poorest of the poor-free blacks and down-and-out whites-saw the fog and gathered up their few possessions for the journey ahead. La Tia, Dead Mary, some sorcerer from up north, they didn't care whom they were following. It couldn't help but be better than here.

But in the rest of the city, in fine houses and the humbler homes of the working class, in hotels and whorehouses and along the dock, where people already cowered in fear of the yellow fever, afraid to go out into the streets-they saw the fog roll through and it looked like a biblical plague to them. I'm not going out in that weather, they thought. I'll send a slave out on my errands. I'll leave the streets to the poor and those whose business is so pressing they'd risk death to carry on with it.

Only in the taverns, where drink brought a few hours of courage and uncontained passion, did the fear burn into hatred. Someone brought this yellow fever on us. It was them French witches, that Dead Mary and her mother, didn't Dead Mary claim the plague for her mother first?

It was those wicked race-mixing abolitionists Moose and Squirrel, they're the ones brought this down on us, cursing the city because they hate us for keeping black folk in the place where God meant them to be. You want proof? All around that house folks is dying of the fever, but not a soul in that crowded house is sick, not a body has been brought out.

"Not Moose and Squirrel, no sir," said a powerful-looking man who carried a knife at his hip the way other men might carry a pistol. "Their house, but it's a traveling man staying there, him and his half-black catamite he uses like a witch does a cat. His name is Alvin and he has a sack full of gold he stole from the smith he was prenticed to. I tell you he brought this fever here. He and his catamite was seen at the public fountain where that magical water was drawn."

They listened spellbound to the man. They itched for action, these men. They had come to Barcy to take part in a war, but the dread of fever had sent the King's army back into their holes, and here they were with nothing to do. Their fingers flexed into fists. The drink burned in them. They could do with a good hanging. Take a man and his slave boy and drag them to a tree or lamppost and hoist them up and watch them clutch and twitch and pee themselves while they strangled on the end of a rope. That was a good use of this foggy night. There'd be no witnesses, and maybe it would stop the fever, and even if it didn't, a hanging was still a good idea now and then, just to get your blood up, and none of this nonsense about an innocent man. Wasn't nobody in this world hadn't earned hanging five times over, if their hearts were only known.

Out of the tavern and into the street they staggered and lurched, shouting threats and brags. A few carried torches against the fog and night as darkness fell over the city, and as they moved near the waterfront, they were joined by the drunk, the angry, the fearful, and the merely curious from other taverns. Where are you going? Off to hang us a traveling wizard and his boy.

The slaves skulking through the streets dodged into alleys or into the shadows of doorways as the mob passed. But they weren't looking to hang the first black man they found. They had a specific man in mind tonight, thanks to that man with the big knife at his belt. They'd find him at the house of Moose and Squirrel-who probably needed hanging too, there being no shortage of rope in Barcy.

Arthur Stuart saw at once that the name "Frenchman's Dock" was meant as a cruel irony. Compared to the miles-long dock along the Mizzippy, this shabby jetty on Lake Pontchartrain was pathetic. Several dozen shrimpboats were tied up to it, and more were coming in, the shrimpers shouting and answering to help each other find their way in the fog. All of them spoke in French, a language in which Arthur was becoming quite fluent, though he suspected the French he was learning here in Nouveau Orleans was not quite the same French that Calvin would have heard in Paris.

There was no room on that busy wharf for fifty children, so Moose and Squirrel kept their family loitering back around the fish houses, trying to stay out of the way. Many of the shrimpers had already heard what was happening tonight. Either they'd come along or not, but there was no debating or discussing it. Everyone stepped around the children and made no comment about their presence there. Even if they wouldn't follow Dead Mary out of the city, they wouldn't dare stand in her way, either.

Blacks began arriving, too, staying even farther out of the way. Like the children, they carried bags and sacks, but it was a sad thing to see how little they had, considering that most of them were carrying all they owned in the world. The blacks who did get in some shrimper's path were met with a growl or a bark to get out of the way; it was clear that even among the oppressed French, blacks had a lower status still.

Flies hovered and swarmed everywhere, there being plenty to feast on for them amid the shrimp offal discarded all along the shore. Skeeters, too, and Arthur Stuart could imagine that with all the people gathering here those little bloodsuckers would probably drink their fill till they bloated up and exploded. He could imagine the sound of it, like distant gunfire, the pop pop pop of busted skeeters.

Only he didn't want them sucking blood out of these children.

He tried to get his doodlebug inside a skeeter, but it wouldn't hold still. And besides, he wasn't looking to perform surgery on it, he wanted to talk to it the way Alvin would, telling it to go away. But he couldn't find the heartfire. It was just too small and faint. Even the heartfires of the big fat lazy flies were almost invisible to him. All the same, he tried talking to the skeeters inside his own mind. "Go away," he said silently. "Nothing to eat here." But if they heard him, they didn't pay him no mind.

A couple of boats ran into each other in the fog, and there was much shouting and cursing. It was silly, Arthur Stuart thought, to put up with fog here, where it wasn't needed. And fog was more like metal or water, he could get inside it and work with it. Arthur Stuart stirred up a little air, drawing a little breeze in from the lake, blowing the fog back toward the city where it was needed.

Arthur was pleased that it didn't take long for the air to clear. The sunset now blazed red in the west, while the fog hung thickly only a street or two back from the water. The shrimpers quickly got their boats tied up and their catch loaded off and dragged into the fish houses. Then they disappeared into the streets, some of them with shrimp carts to sell the catch, the others probably heading for their families, to bring them to Frenchman's Dock for the escape.

There being no more need for clear vision now, Arthur Stuart let the breeze die down, and the fog drifted back out over the water a little. Stillness came with it, a heavy silence in which footfalls were muffled and voices became whispers.

As it became fully dark, Arthur began to worry about folk losing their way, or somebody stumbling into the water, so he woke up the breeze again to clear the air near the shore. In the distance, he could hear shouting, and after a while, he realized that it was probably the noise of a mob moving through the streets of Barcy. He worried about folks who was trying to make their way through the streets, but the fog was the best help they could get, and there wasn't nothing Arthur Stuart could think of to add to it.