"With fatal results," Corvus said. "They set something loose in this world that doesn't belong in it."

"The Corpusant," Ward whispered.

Corvus raised his eyebrows.

"Maude told me about it," Ward explained.

"Who's Maude?" Carmen said.

Ward went on as if he hadn't heard her. "She couldn't tell me what it was."

"That's because the Wise Old Woman," Corvus gave Carmen an apologetic look, "doesn't know. Nobody does – not really."

"How did they do it?" Ward said.

"They weren't trying to," Corvus said. "It was an accident that occurred during one of their experiments. The fabric that separates this world from another was torn slightly. It was an infintesimal rent – smaller than you would be able to see with your naked eye – on the level of the minute particles that are the building blocks of everything you can see and touch. In the instant of time this tear was open, something slipped through it. Something from Outside. Not from another world, but from the darkness between them.

"Corpusant means walking fire. In ancient times there were prophets who claimed to have been visited by fiery gods. In those old stories the gods revealed themselves in burning bushes, columns of fire – that sort of thing. I suspect some of these stories came from visions like those the Old Wise Woman has, for if they had seen a corpusant in person they would not have lived to tell of it. It's a common aspect of these stories that if the god were to reveal its true form the mortal would be blasted into oblivion. The prophets often spoke to these fiery presences, received instructions, or were given glimpses into the future. Corpusants are capable of speech, after a fashion. They are composed, as far as I know, of light itself. Radiation."

"Sunlight can burn you," Carmen said.

"Sunlight contains several kinds of radiation. If not for our atmosphere," he pointed up at the ceiling, "radiation from the sun would kill us rather quickly and horribly."

"What happened when it got out?" Ward said.

"A corpusant in its natural form would find our environment hostile. It would some kind of protective shell to survive. A human host. When the Corpusant emerged it immediately consumed one of the scientists."

"And it escaped in their body?" Carmen said.

"Yes. Nobody – nothing would have been able to stand in its path."

"Where did it go?" Carmen said.

"Nobody knows. There were reports of great forest fires for a while, but that was not unusual in and of itself. Some strange accounts of lakes boiling. Premature thawing in high latitudes. Then the virus came, and nothing else mattered for a long time. As far as I can tell the Corpusant went into hiding. Or there simply weren't enough people around to notice it. Those who survived an enconter would have had no way of reporting it beyond their immediate communities. Many mythic traditions of fiery beings have arisen in the intervening years; it's possible some of these sprang from sightings. It didn't appear to seek out people."

"What does it want?" Ward said.

"Who knows? It might not want things at all. Its mind is incomprehensible to us."

"But isn't it also a person?" Ward said.

"It needs the body of its human host to shelter in. Whether any remnant of her mind remains – whether she could have survived that – I don't know." Corvus looked down at his hands.

"She?" Carmen said.

"The scientist was a woman."

"So the Corpusant still out there?" Ward said.

"No," Corvus said, looking up from his hands. "It was captured."

It's just a hunk, a hunk of burning love.