“Slake-moths are very rare. And a state secret. That is why we were so excited about our little clutch of the things. We had one old, dying specimen, then received four new grubs. Isaac had one, of course. The original, that had fed our little caterpillars, died. We were debating whether to open the cocoon of another during its change, killing it but gleaning invaluable knowledge of its metamorphic state, but before we had decided, regrettably,” he sighed, “we had to sell all four. They were an excessive risk. The word came that our research was taking too long, that our failure to control the specimens was making the…ah…paymasters nervous. Funding was withdrawn, and our department had to pay its debts quickly, given the failure of our project.”

“Which was what?” hissed Isaac. “Weapons? Torture?”

“Oh, really, Isaac,” said Vermishank calmly. “Look at you, stiff with moral outrage. If you hadn’t stolen one of them in the first place, it would never have escaped, and it would never have freed its fellows-which is what must have happened, you realize-and think how many innocent people would have lived.”

Isaac stared at him aghast.

“Fuck you!” he screamed. He rose and would have leapt at Vermishank had Lemuel not spoken.

“Isaac,” he said curtly, and Isaac saw that Lemuel’s gun was trained on him. “Vermishank is being very co-operative and there’s more we need to know. Right?”

Isaac stared at him, nodded and sat.

“Why are you being so helpful, Vermishank?” asked Lemuel, returning his gaze to the older man.

Vermishank shrugged.

“I do not relish the idea of pain,” he said with a little simper. “In addition to which, although you will not like this…it will do you no good. You cannot catch them. You cannot evade the militia. Why would I hold back?” He gave a smug, loathsome grin.

And yet his eyes were nervous, his upper lip sweating. There was a forlorn note buried deep in his throat.

Godspit! thought Isaac with a sudden shock of realization. He sat up and stared at Vermishank. That is not all! He…he’s telling us because he’s afraid! He doesn’t think the government can catch them…and he’s afraid. He wants us to succeed!

Isaac wanted to taunt Vermishank with this, to wave the knowledge of his weakness at him, to punish him for all his crimes…but he would not risk it. If Isaac were to antagonize him too flagrantly, to confront him with an understanding of his fear that Isaac doubted Vermishank himself possessed, then the vile man might withdraw all his help out of spite.

If he needed to think he was crowing to beg for help, then Isaac would let him.

“What is dreamshit?” said Isaac.

“Dreamshit?” Vermishank smiled, and Isaac remembered the last time he had asked Vermishank that question and the man had affected disgust, had refused to sully his mouth with the foul word.

It came easy to him now.

“Hah. Dreamshit is baby food. It is what the moths feed their young. They exude it all the time, but in great quantities when they are parenting. They are not like other moths: they’re very caring. They nurture their eggs assiduously, by all accounts, and suckle the newborn caterpillars. Only in their adolescence, when they pupate, can they feed themselves.”

Derkhan interjected.

“Are you saying that dreamshit is slake-moth milk?”

“Exactly. The caterpillars cannot yet digest purely psychic food. It must be imbibed in quasi-physical form. The liquid the moths exude is thick with distilled dreams.”

“And that’s why some fucking druglord bought them? Who was it?” Derkhan’s mouth curled.

“I have no idea. I merely suggested the deal. Which of the bidders was successful is irrelevant to me. One has to husband the moths carefully, stud them regularly, milk them. Like cows. They can be manipulated-by someone who knows what they’re doing-fooled into exuding milk without having born grubs. And the milk has to be processed, of course. No human, or any other sentient race, could drink it neat. It would instantly explode their mind. The inelegantly named dreamshit has been rendered and…ah…cut with various substances…Which incidentally, Isaac, means that the caterpillar you raised-that I presume you fed on dreamshit-must have grown into a less than healthy moth. It is as if you fed a human baby milk laced with large quantities of sawdust and pondwater.”

“How do you know all this?” hissed Derkhan.

Vermishank looked at her blankly.

“How do you know how many mirrors it takes to make you safe, how do you know they turn the minds they…they eat into that…milk…? How many people have you fed to them?”

Vermishank pursed his lips, a little perturbed.

“I am a scientist,” he said. “I use the means at my disposal. On occasion, criminals are sentenced to death. The manner of their death is not specified…”

“You swine…” she hissed viciously. “What about all the people the dealers take to feed them, to make the drug…?” she continued, but Isaac cut her off.

“Vermishank,” he said softly, and stared at the other man. “How do we get their minds back? The ones who’ve been taken.”

“Back?” Vermishank seemed genuinely baffled. “Ah…” He shook his head and furrowed his eyes. “You cannot.”

“Don’t lie to me…” screamed Isaac, thinking of Lublamai.

“They have been drunk,” hissed Vermishank, and brought silence quickly to the room. He waited.

“They have been drunk” he said again. “Their thoughts have been taken, their dreams-their conscious and subconscious-have been burnt up in the moths’ stomachs, have trickled out again to feed the grubs. Have you taken dreamshit, Isaac? Any of you?” No one, least of all Isaac, would answer him. “If you have, you have dreamed them, the victims, the prey. You have had their metabolized minds slip into your stomach and you have dreamed them. There is nothing left to save. There is nothing to get back.”

Isaac felt absolute despair.

Take his body too, he thought, Jabber, don’t be cruel, don’t leave me with that fucking shell that I can’t let die, that means nothing…

“How do we kill the slake-moths?” he hissed.

Vermishank smiled, very slowly.

“You cannot,” he said.

“Don’t bullshit me,” hissed Isaac. “Everything that lives can die…”

“You misunderstand me. As an abstract proposition of course they can die. And therefore, theoretically, they can be killed. But you will not be able to kill them. They live in several planes, as I’ve said, and bullets, fire, and so forth injure only in one. You would have to hit them in many dimensions at once, or do the most extraordinary amount of damage in this one, and they will not give you the chance…Do you understand?”

“So let’s think laterally…” said Isaac. He batted his temples hard with the heels of his hands. “What about a biological control? Predators…”

“They have none. They are at the top of their food chain. We’re fairly sure that there are animals, in their native land, that are capable of killing them, but there are none within several thousand miles of here. And anyway, if we’re right, to unleash them would be to usher doom more quickly onto New Crobuzon.”

“Dear Jabber,” breathed Isaac. “Without predators or competitors, with a massive supply of food, fresh and constantly replenished…There’ll be no stopping them.”

“And that,” whispered Vermishank hesitantly, “is before we’ve even considered what’ll happen if they…They are still young, you understand. They are not fully mature. But soon, when the nights become hot…We have to consider what might happen when they breed…”