And if I didn’t get the cat back, ditto.

“Well, we don’t want to lose any battles on the morrow,” I said, trying again, “so we’d best get to bed.”

“Individual action,” Professor Peddick said, puffing on his pipe. “That’s what lost the Battle of Hastings. The Saxons had the advantage, you know. They were drawn up on a ridge. Being on a defended height is the greatest military advantage an army can have. Look at Wellington’s army at Waterloo. And the battle of Fredericksburg in the American Civil War. The Union army lost twelve thousand men at Fredericksburg, marching across an open plain to a defended height. And England was a richer country, fighting on their own home ground. If economic forces are what drives history, the Saxons should have won. But it wasn’t forces that won the Battle of Hastings. It was character. William the Conqueror changed the course of the battle at at least two critical points. The first came when William was unhorsed during a charge.”

Cyril lay down and began to snore.

“If William had not gotten immediately to his feet and pushed back his helmet so that his men could see that he was alive, the battle would have been lost. How does Overforce fit that into his theory of natural forces? He can’t! Because history is character, as is proved by the second crisis point of the battle.”

It was a full hour before they knocked the tobacco out of their pipes and started down to the boat. Halfway there, Terence turned and came back. “Perhaps you’d better take the lantern,” he said, holding it out to me, “since you’re sleeping on shore.”

“I’ll be perfectly all right,” I said. “Good night.”

“Good night,” he said, starting down to the boat again. “ ‘Night is the time for rest.’ ” He waved to me. “ ‘How sweet when labors close, To gather round an aching breast the curtain of repose.’ ”

Yes, well, it would be, but I had a cat to find first. I went back to the clearing to wait for everyone to go to sleep, trying not to think about how every moment the cat was loose the number of consequences multiplied exponentially.

It might have been eaten by a wolf. Did Victorian England have wolves? Or found by an old woman in a cottage and taken in. Or picked up by a passing boat.

The locks are closed, I told myself, and it’s only a cat. How much of an effect on history can an animal have?

A big one. Look at Alexander the Great’s horse Bucephalus, and “the little gentleman in the black fur coat” who’d killed King William the Third when his horse stepped in the mole’s front door. And Richard the Third standing on the field at Bosworth and shouting, “My kingdom for a horse!” Look at Mrs. O’Leary’s cow. And Dick Whittington’s cat.

I waited half an hour and then cautiously lit the lantern. I took the tins out from their hiding place and pulled the tin-opener out of my pocket. And tried to open them.

It was definitely a tin-opener. Terence had said it was. He’d opened the peaches with it. I poked at the lid with the point of the scimitar and then with the side of it. I poked at it with the other, rounded edge.

There was a space between the two. Perhaps one fit on the outside of the tin as a sort of lever for the other. Or perhaps it went in from the side. Or the bottom. Or perhaps I was holding it the wrong way round, and the scimitar thing was the handle.

That resulted in a hole in the palm of my hand, not exactly the idea. I rummaged through the satchel for a handkerchief to wrap round it.

All right, look at the thing logically. The point of the scimitar had to be the part that went through the tin. And it had to go through the lid. Perhaps there was a specific place in the lid where it fit. I examined the lid for weaknesses. It hadn’t any.

“Why did the Victorians have to make everything so bloody complicated?” I said and saw a flicker of light at the near edge of the clearing.

“Princess Arjumand?” I said softly, holding up the lantern, and I had been right about one thing. Cats’ eyes did glow in the dark. Two were shining yellowly at me from the bushes.

“Here, cat,” I said, holding out the heel of bread and making “tsk”ing noises. “I’ve got some food for you. Come here.”

The glowing eyes blinked and then disappeared. I stuck the bread in my pocket and started carefully for the edge of the clearing. “Here, cat. I’ll take you home. You want to go home, don’t you?”

Silence. Well, not exactly silence. Frogs croaked, leaves rustled, and the Thames made a peculiar gurgling sound as it flowed past. But no cat sounds. And what sounds did cats make? Since all the cats I’d ever seen had been asleep, I wasn’t sure. Meowing sounds. Cats meowed.

“Meow,” I said, lifting branches to look under the bushes. “Come here, cat. You wouldn’t want to destroy the space-time continuum, would you? Meow. Meow.”

There the eyes were again, past that thicket. I set off through it, dropping bread crumbs as I went. “Meow?” I said, swinging the lantern slowly from side to side. “Princess Arjumand?” and nearly tripped over Cyril.

He wagged his nether half happily.

“Go back and sleep with your master,” I hissed. “You’ll just get in the way.”

He immediately lowered his flat nose to the ground and began snuffling in circles.

“No!” I whispered. “You’re not a bloodhound. You haven’t even got a nose. Go back to the boat.” I pointed toward the river.

He stopped snuffling and looked up at me with bloodshot eyes that could have been a bloodhound’s and an expression that clearly said, “Please.”

“No,” I said firmly. “Cats don’t like dogs.”

He began snuffling again, what passed for his nose earnestly to the ground.

“All right, all right, you can come with me,” I said, since it was obvious he was going to anyway. “But stay with me.”

I went back into the clearing, poured the cream into a bowl, and got the rope and some matches. Cyril watched interestedly.

I held the lantern aloft. “ ‘The game’s afoot, Watson,’ ” I said, and we set off into the wilderness.

It was very dark, and along with the frogs, river, and leaves were assorted slitherings and rattlings and hoots. The wind picked up, and I sheltered the lantern with my hand, thinking what a wonderful invention the pocket torch was. It gave off a powerful light, and one could point the beam in any direction. The lantern’s light I could only direct by holding it up or down. It did give off a warm, wavering circle of light, but its only function seemed to be to make the area outside said circle as black as pitch.

“Princess Arjumand?” I called at intervals, and “Here, cat,” and “Yoo hoo.” I dropped bread crumbs as I went, and periodically I set the dish of cream down in front of a likely looking bush and waited.

Nothing. No glowing eyes. No meows. The night got darker and damper, as if it might rain.

“Do you see any sign of her, Cyril?” I asked.

We trudged on. The place had looked quite civilized this afternoon, but now it seemed to be all thornbushes and tangled underbrush and sinister clawlike branches. The cat could be anywhere.

There. Down by the river. A flash of white.

“Come on, Cyril,” I whispered and started toward the river.

There it was again, in the midst of some rushes, unmoving. Perhaps she was asleep.

“Princess Arjumand?” I said and reached through the reeds to pick her up. “There you are, you naughty thing.”

The white suddenly rose up, revealing a long, curving neck.

“Squaw-w-w!” it said, and exploded into a huge white flapping. I dropped the dish with a splash.

“It’s a swan, I said unnecessarily. A swan. One of the ancient beauties of the Thames, floating serenely along the banks with their snowy feathers and their long graceful necks. “I’ve always wanted to see one,” I said to Cyril.

He wasn’t there.

“Squaww-w-w-k!” the swan said and unfolded its wings to an impressive width, obviously irritated at being awakened.