"He was using a slave. Apparently they had wizard slaves, maybe from conquering another city and enslaving everyone — they used to do that. He doesn't say how you poison mana and we don't have any slaves."

"And wouldn't feed one to a Brume if we did.

"I don't believe it would work — mana only has two states. Does it say he ever actually did it?"

Mari shakes her head.

"No. Maybe someone asked him for a solution to the problem so he made one up."

"If we did have some way of poisoning mana we could put it in a leaky crystal and throw it at the Brumes. But we don't, and I cannot see how we could.

"But the idea that mana is all they see might still be useful somehow."

"Yeah, that sounds like a harder problem than scaling up the mal-solidifier. I vote we go back to the stacks."

Ellen nods, puts the book she was carrying on top of one of the dictionaries.

"Is there anything special or any language we should be looking for, beyond Brumes and immaterials and solidifying? Mari has better luck in the library than most people. She even found a copy of Von Neumann and Morgenstern for a nice African boy who wanted to know about game theory."