But by the time I got there, the firm was gone, and their shop was just this big smoking hole in the ground. I could have told them MORE BANG FOR YOUR BUCK was a really bad idea for a slogan ... Anyway, I got side-tracked to China, where I found... that."

And she indicated one of the smaller display cases with a dramatic gesture and a sprinkling of ash because she'd forgotten the cigarette in her hand. She muttered a series of baby swear words and brushed the ash off the top of the case, while I leaned forward for a closer look. Behind the glass was a single butterfly, not particularly big or small, or especially pretty. In fact, it looked distinctly ordinary. It hung in mid air, in mid-flight, wings extended, surrounded by the faint shimmer of a stasis field. The butterfly had been frozen in a moment of Space and Time, like an insect preserved in amber. I looked back at Wilde, but again she got in first while I was still raising an eyebrow. "Yes, it's rare, but not in the way you think. The explanation's a bit complex, but try and keep up. Chaos theory says that if a butterfly flaps its wings over China, we end up with a storm over America. Since everything in the world is connected, or at least on speaking terms. So, if you could identify and track down that particular butterfly ... Well, I have, and there it is. The little troublemaker. A wonderfully unique item, which I intend to let go for an equally unique price. Oh, the Collector is going to be so jealous!"

(Wilde and the Collector had a thing going once. It didn't work out. No-one ever thought it would, but you just can't tell some people.)

"The butterfly theory is nothing new, really," said Grave, in her most academic and tweedy voice. Auctioneers always sound like failed scholars. Probably because most of them are. "The ancient Romans had people called Augurs who could predict the future by studying the flight of birds."

Wilde gave her a withering look. "They also had a tendency to cut open goats, then accuse people of treason over which way the goat's liver was pointing. And give themselves lead poisoning with their choice of plumbing materials."

"Let us all make a valiant effort to stick to the point, please," I said. "Isn't the whole butterfly thing just a metaphor? There isn't a real butterfly, as such."

Wilde hit me with her most withering smile. "Metaphors can be as real as anything else in the Night-side, darling. Symbols can have their own identity here. So, whatever lucky person takes possession of this butterfly at auction will possess the power to identify all such butterflies; the first domino in the line that will produce fu ture events. The owner should then be able to predict and possibly even control the way the future turns out. The possibilities are endless! In theory, anyway. Trust me on this, John darling; I am going to be rich, rich, rich!"

"If it's so potentially powerful, why are you so ready to give it up?" I asked.

Wilde struck her best Why am I beset by fools of no vision pose. "John. Darling. I am not stupid enough to try and keep anything this earth-shattering for myself. I'd have to spend all my time fighting off major players who wanted to take it away from me. And you can bet the Faerie wouldn't deign to get involved, the ungrateful little shits. No, an auction, on famously neutral ground, is the best way to make a substantial profit on this little beauty." She blew a kiss at the butterfly in its case. "And then I shall take all the money and run, all the way back to the Unseeli Court, and not show my head again until the last of the shooting's died down."

"Given the clear potential for things to get really nasty really quickly, I'm surprised the Authorities haven't stepped in to confiscate the butterfly," I said, frowning. "Walker doesn't normally approve of anything that threatens to upset his precious status quo."

"Walker might like to think he's in charge of things round here," Wilde said dismissively, "but the Authorities have always understood that free enterprise has to come first."

"Philistines," said Grave, polishing her monocle furiously.

"Or," I said, "perhaps the Authorities don't believe this butterfly is the real thing, either."

Wilde smiled widely and blew a perfect smoke ring. "Don't care was made to care,