Mr. Dunworthy cut him off. “What’s Fujisaki’s other theory?”

“His second theory is that there are incongruities, but that the continuum has built-in defenses that counteract them.”

“Slippage,” Mr. Dunworthy said.

T.J. nodded. “The mechanism of slippage prevents nearly all potential incongruities by removing the time traveller from the area of potential danger. Fujisaki’s theory is that the amount of slippage is limited, and that an incongruity occurs when the slippage can’t increase radically enough to prevent the parachronism.”

“What happens then?”

“Theoretically it could alter the course of history, or, if it were severe enough, destroy the universe, but there are safeguards in the modern net to prevent that. As soon as the danger of incongruities was realized, the net was modified to automatically shut down whenever the slippage reaches dangerous levels. And Fujisaki says that if an incongruity did occur, which it can’t, there are other lines of defense that would correct the incongruity and would manifest themselves as,” he read from the paper, “radically increased slippage in an area surrounding the incongruity, an increase in coincidental events—”

Mr. Dunworthy turned to me. “Did you experience any coincidences in Coventry?”

“No,” I said.

“What about your jumble sales?”

“No,” I said, thinking how nice it would have been if I had experienced one, if, strolling between the coconut shy and the plum-cake raffle, I had run bang into the bishop’s bird stump.

Mr. Dunworthy turned back to T.J. “What else?”

“Increased slippage in the peripheral temporal areas.”

“How large an area?”

He bit his lip. “Fujisaki says most incongruities are corrected within fifty years, but this is all theoretical.”

“What else?”

“If it were really serious, a breakdown in the net,” T.J. said.

“What sort of breakdown?”

He frowned. “Failure of the net to open. Malfunction in destination. But Fujisaki says those are all statistically unlikely,” T.J. said, “and that the continuum is essentially stable or it would have been destroyed by now.”

“What if there was no radical increase in slippage, but it was definitely an incongruity?” Mr. Dunworthy said. “Would that mean it had been corrected before it could have any effect on the continuum?”

“Yes,” T.J. said. “Otherwise there’d have to be slippage.”

“Good. Excellent job, Ensign Klepperman,” Mr. Dunworthy said. He went over to the seraphim, who was violently banging keys at the console. “Warden, I want a list of all the drops we’ve done to the 1880s and ‘90s with the recorded amount of slippage and the normal parameters.”

“It’s Warder,” the seraphim said. “And I can’t do it now. I’ve got a rendezvous.”

“The rendezvous can wait.” He went back over to T.J. “Lewis, I want you to look for unusual slippers.”

Or at least that’s what I thought he said. The All-Clear had started up again, and now it was accompanied by a steady, thumping throb, like ack-ack guns.

“And chicken drops.”

“Yes, sir,” T.J. said and left.

“Finch, where’s the hat?” Mr. Dunworthy said.

“Right here,” Finch said, and that couldn’t be right either. I had white flannels and a waistcoat, but no hat. And Victorians always wore hats, didn’t they? Top hats and those hard round affairs, what were they called? It began with an “N.”

The seraphim was leaning over me, which meant I must have sat down again. She stood me up to try on blazers.

“Put your arm in this one,” she said, thrusting a maroon-striped one at me. “No, your right arm.”

“The sleeves are too short,” I said, looking at my bare wrists.

“What’s your name?”

“My name?” I said, wondering what that had to do with the sleeves being too short.

“Your name!” she said, yanking off the maroon-striped blazer and shoving a red one at me.

“Ned Henry,” I said. The sleeves of this one came down over my hands.

“Good,” she said, stripping it off and handing me a dark-blue-and-white one. “At least I won’t have to come up with a contemp name for you.” She tugged on the sleeves. “That’ll have to do. And don’t go diving into the Thames. I haven’t time to do any more costumes.” She clapped a straw boater on my head.

“The hat was here. You were right, Mr. Dunworthy,” I said, but he wasn’t there. Finch wasn’t either, and the seraphim was back at the console, banging away at the keys.

“I can’t believe Badri isn’t back yet,” she said. “Leaving me with this lot. Set the coordinates. Come up with a costume. And meanwhile, I’ve got an historian waiting three-quarters of an hour to come through. Well, your priority jump can jolly well wait for unmarried girls were constantly accompanied by chaperones, usually an older maiden aunt or cousin, and were never allowed to be alone with a man until after their engagement, Ned, pay attention.”

“I am,” I said. “Unmarried girls were always accompanied by chaperones.”

“I told you I didn’t think this was a good idea,” Finch, who was there, too, said.

“There’s nobody else to send,” Mr. Dunworthy said. “Ned, listen carefully. Here’s what I want you to do. You’ll come through on June the seventh, 1888, at ten A.M. The river is to the left of the dessert fork, which is used for gateaux and puddings. For such desserts as Muchings End, the dessert knife is used with the…”

Knife. Nice. Naiads. That was what they were called. Hylas and the Naiads. He went to fill his water jug, and they pulled him into the water with them, down and down, their hair and their wet sleeves twining about him.

“As soon as it’s returned, you can do whatever you like. The rest of the two weeks is yours. You can spend it boating on the river or to the right of the dessert plate, with the blade pointing inward.” He clapped me on the shoulder. “Have you got that?”

“What?” I said, but Mr. Dunworthy wasn’t listening. He was looking at the net. There was a loud hum that threatened to drown out the ack-ack guns, and the veils on the net began to lower.

“What’s that?” Mr. Dunworthy said to the seraphim.

“The rendezvous,” she said, pounding keys. “I couldn’t very well leave him there forever. I’ll do your drop as soon as I bring him through.”

“Good,” Mr. Dunworthy said. He clapped me on the shoulder. “I’m counting on you, Ned,” he said through the hum.

The veils touched the floor, draping gently. The hum rose in pitch till it sounded like the All-Clear, the air shimmered with condensation, and Carruthers appeared inside the net. He began fighting with the veils to get out.

“Stand still and wait till the veils have raised,” the seraphim ordered, pounding keys. The veils rose a foot and a half and stopped.

“Wait?” Carruthers said, ducking under them. “Wait? I’ve been waiting for two bloody hours!” He flailed at the fabric of the veils. “Where the bloody hell were you?”

He worked himself free and limped toward the console. He was covered in mud. He had lost one of his boots, and the front of his non-AFS uniform had a long, flapping tear in the back of one leg. “Why the hell didn’t you come get me as soon as you got the fix and saw where I’d landed?”

“I was interrupted,” she said, glaring at Mr. Dunworthy. She crossed her arms militantly. “Where’s your boot?”

“In the mouth of a bloody great mastiff! I was lucky to get away with my foot!”

“That was an authentic AFS Wellington,” she said. “And what have you done to your uniform?”

“What have I done to my uniform?” he said. “I’ve just spent two hours running for my life. I landed in that same damnable marrows field. Only I must have come through later than last time because the farmer’s wife was ready for me. With dogs. She’d recruited a whole bloody pack of them to aid in the war effort. She must have borrowed them from all over Warwickshire.”