“A vapor trail. How many people have read the story of Peter Pan? How many children have watched a cartoon or a film? How many of them have imagined Kensington Gardens and Peter? How many of those were overt or potential Others?”

“We can’t create people.”

“Any woman can do that,” Arina laughed. “But we’re talking about something different here. An image—one that has been adequately visualized—is projected onto a point at which there is already an immense concentration of Power. The Power at the various levels of the Twilight starts to get agitated. The energy is stabilized at a higher level. You can calculate it using the Boltzmann Distribution, the whole process is almost identical to thermodynamic equations, you can even use Planck’s Constant—only for the twilight it’s called the Canterbury Constant.”

I suddenly realized that I was sitting there with my mouth wide open, holding a fork with a piece of fried egg suspended on it. I hurriedly clamped my mouth shut, biting the fork painfully, and swore in a whisper.

“It’s the standard process for the appearance of ghosts,” Arina continued. “Don’t the Light Ones teach that these days?”

“No,” I admitted. “And the Dark Ones don’t, either . . . probably.”

“Well, they should,” said Arina. “It’s no practical use at all, but surely you must be interested in where phantoms come from, the life of the Twilight, which spells will be most effective at what point in space?”

“I didn’t even know it was possible”—I hesitated—“to reduce it all to formulas.”

“But Witches have always known that,” Arina told me. “Surely you don’t think that Witches are dirty old women who boil up unappetizing substances in cauldrons and mutter ‘by the pricking of my thumbs’ . . . ?”

I thought it best not to say anything. Arina drank her coffee, clearly savoring the situation.

“Well, what have you decided?” she asked insistently.

“The mere fact that I’m talking to you without trying to arrest you is official misconduct,” I said gruffly.

Arina snorted.

“Swear on the Light and the Darkness,” I said.

Arina raised her eyes to look at me.

“Swear that you had nothing to do with the dream I had last night,” I went on.

“So things are that bad, are they?” Arina said, with an understanding nod. “All right . . .”

She said nothing for a few seconds, as if she was trying to recall something. Then she reached her hands out across the table and turned them palms upwards.

I was scalded by a chilly breath of wind.

The few other hotel guests all turned away and diligently stopped noticing us.