“There wouldn’t have been room for radically increased slippage, would there?” I said. “Lizzie Bittner had to go in within a very narrow window of time — between the time the treasures were last seen and their destruction by the fire. She only had a few minutes. Increased slippage would have put her right in the middle of the fire.”

“Yes, well, even taking that into consideration, there is still the problem of the surrounding slippage,” he said, pointing at nothing. “So,” he said, flicking some more keys, “I tried moving the focus forward.” A nondescript gray picture came up.

“Forward?”

“Yes. Of course, I didn’t have enough data to pick a space-time location like you did, so what I did was to consider the surrounding slippage to be peripheral and to extrapolate new surrounding slippage, and then extrapolate a new focus from that.”

He called up another gray picture. “Okay, this is the model of Waterloo. I’m going to superimpose it over the model with the new focus.” He did. “You can see it matches.”

I could. “Where does that put the focus?” I said. “What year?”

“2678,” he said.

2678. Over six hundred years in the future.

“The fifteenth of June, 2678,” he said. “As I said, it’s probably nothing. An error in the calculations.”

“And if it isn’t?”

“Then Mrs. Bittner’s bringing the bishop’s bird stump through isn’t the incongruity.”

“But if it isn’t the incongruity… ?”

“It’s part of the self-correction as well,” T.J. said.

“The self-correction of what?”

“I don’t know,” he said. “Something that hasn’t happened yet. Something that’s going to happen in—”

“—in 2678,” I said. “What’s the focus’s location?” I asked, wondering if it would be as far-flung as the date. Addis Ababa? Mars? The Lesser Magellanic Cloud?

“Oxford,” he said. “Coventry Cathedral.”

Coventry Cathedral. On the fifteenth of June. Verity had been right. We were intended to find the bishop’s bird stump and return it to the cathedral. And all of it, the selling of the new cathedral and Lady Schrapnell’s rebuilding of the old one and our discovery that nonsignificant treasures could be brought forward through the net were all part of the same huge self-correction, some Grand—

“I’m going to double-check all the calculations and run some logic tests on the model,” T.J. said. “Don’t worry. It’ll probably turn out to be nothing more than a flaw in the Waterloo sim. It’s only a rough model.”

He touched some keys, and the gray disappeared. He began folding up the screen.

“T.J.,” I said. “What do you think determined the outcome of the Battle of Waterloo? Napoleon’s handwriting or his hemorrhoids?”

“Neither,” he said. “And I don’t think it was any of the things we did sims on — Gneisenau’s retreat to Wavre or the lost messenger or the fire at La Sainte Haye.”

“What do you think it was?” I asked curiously.

“A cat,” he said.

“A cat?”

“Or a cart or a rat or—”

“—the head of a church committee,” I murmured.

“Exactly,” he said. “Something so insignificant no one even noticed it. That’s the problem with models — they only include the details people think are relevant, and Waterloo was a chaotic system. Everything was relevant.”

“And we’re all Ensign Kleppermans,” I said, “suddenly finding ourselves in positions of critical importance.”

“Yeah,” he said, grinning, “and we all know what happened to Ensign Klepperman. And what’s going to happen to me if I don’t get over to the vestry. Lady Schrapnell wants me to light the candles in the chapels.” He hastily grabbed up the screen and the comp setup. “I’d better get busy lighting. It looks like they’re about to begin.”

It did. The choirboys and dons were more or less lined up, the woman in the green apron was gathering up scissors and buckets and flower-wrappings, the boy had come out from under the choir stall. “Is the trumpet stop working now?” a voice called down from the clerestory, and the organist shouted back, “Yes.” Carruthers and Warder were standing by the south door, their arms full of orders of service and each other. I went out into the nave, looking for Verity.

“Where have you been?” Lady Schrapnell said, bearing down on me. “I have been looking all over for you.” She put her hands on her hips. “Well,” she demanded. “I thought you said you’d found the bishop’s bird stump. Where is it? You haven’t lost it again, have you?”

“No,” I said. “It’s in front of the parclose screen of the Smiths’ Chapel where it’s supposed to be.”

“I want to see it,” she said and started for the nave.

There was a fanfare, and the organist launched into “O God Who Doeth Great Things and Unsearchable.” The choirboys opened their hymnals. Carruthers and Warder pulled apart and took up their positions by the south door.

“I don’t think there’s time,” I said. “The consecration’s about to start.”

“Nonsense,” she said, barging through the choirboys. “There’s plenty of time. The sun isn’t out yet.”

She pushed through the dons, parting them like the Red Sea, and started down the north aisle to the Smiths’ Chapel.

I followed her, hoping the bishop’s bird stump hadn’t mysteriously disappeared again. It hadn’t. It was still there, on its wrought-iron flower stand. The woman in the green apron had filled it with a lovely arrangement of white Easter lilies.

“There it is,” I said, presenting it proudly. “After untold trials and tribulations. The bishop’s bird stump. What do you think?”

“Oh, my,” she said, and pressed her hand to her bosom. “It really is hideous, isn’t it?”

“What?” I said.

“I know my great-great-great-great-grandmother is supposed to have liked it, but my God! What is that supposed to be?” she said, pointing at the base. “Some kind of dinosaur?”

“The Signing of the Magna Carta,” I said.

“I’m almost sorry I had you waste so much time looking for it,” she said. She looked thoughtfully at it. “I don’t suppose it’s breakable?” she said hopefully.

“No,” I said.

“Well, I suppose we have to have it for authenticity’s sake. I certainly hope the other churches don’t have anything this hideous in them.”

“Other churches?” I said.

“Yes, haven’t you heard?” she said. “Now that we’re able to bring objects forward through the net, I have all sorts of projects planned. The San Francisco earthquake, the MGM back lot, Rome before the fire Julius Caesar set—”

“Nero,” I said.

“Yes, of course. You will have to bring back the fiddle Nero played.”

“But it didn’t burn in the fire,” I said. “Only objects that have been reduced to their component parts—”

She waved her hand dismissively. “Laws are made to be broken. We’ll start with the fourteen Christopher Wren churches that were burned in the Blitz, and then—”

“We?” I said weakly.

“Yes, of course. I’ve already specifically requested you.” She stopped and glared at the bishop’s bird stump. “Why are those lilies? They are supposed to be yellow chrysanthemums.”

“I think lilies are extremely appropriate,” I said. “After all, the cathedral and all its treasures have been raised from the dead. The symbolism—”

She wasn’t impressed with the symbolism. “The order of service says yellow chrysanthemums,” she said. “ ‘God is in the details.’ ” She stormed off to find the poor defenseless woman in the green apron.

I stood there, looking at the bishop’s bird stump. Fourteen Christopher Wren churches. And the MGM back lot. To say nothing of what she might come up with when she Realized What It Meant.

Verity came up. “What’s wrong, Ned?” she said.

“I am fated to spend my entire life working for Lady Schrapnell and attending jumble sales,” I said.

“Pish-tosh!” she said. “You are fated to spend your life with me.” She handed me the kitten. “And Penwiper.”

The kitten didn’t weigh anything. “Penwiper,” I said, and it looked up at me with gray-green eyes.