“Come on,” I said, taking her hand as if she were a child. “We’re going to go now. This way.”

I led her behind the lilacs and down the path to the river. Cyril and Princess Arjumand followed us, Princess Arjumand twining herself around our legs as we walked and impeding our progress.

“Cyril,” I whispered, “go find Terence.”

“Good idea,” Verity said. “I have a few things to say to Terence. ‘Terence,’ I’m going to say to him, ‘how can you be in love with someone who hates your dog?’ ”

We reached the towpath. “Shh,” I said, listening for Professor Peddick.

“Through art, through history, we may glimpse the Grand Design,” he said. His voice sounded farther away. “But only for a fleeting moment. ‘For His works are unsearchable and His ways past finding out,’ ” he said, his voice growing fainter. They must be going up to the house.

“I’ll bet Maud Peddick loves dogs,” Verity said. “She’s a lovely girl. She doesn’t keep a diary, she’s patriotic—”

There was no one down at the dock. I propelled Verity rapidly down the path to the river.

“She’s got a poem named after her,” Verity said. “ ‘Come into the garden, Maud, I am here at the gate alone.’ By Tennyson. Terence loves quoting Tennyson. When Maud Peddick screams, I’ll bet it’s the real thing and not some little baby scream. Oh, are we going in a boat?”

“Yes,” I said, helping her in. “Sit down.”

She stood, swaying slightly, in the stern, gazing wistfully out at the river. “Lord Peter took Harriet out boating,” she said. “They fed the ducks. Are we going to feed the ducks?”

“You bet,” I said, untying the rope. “Sit down.”

“Oh, look,” she said, pointing at the shore. “They want to come. Isn’t that sweet?”

I jerked my head up and looked at the shore. Cyril and Princess Arjumand were standing side by side on the little dock.

“Can’t Cyril come?” she said.

The thought of trying to rescue two dead weights if they went overboard was not appealing. On the other hand, if we took them with us, the Black Moor would be safe. And if Finch was trying to drown Princess Arjumand, she was safer with me.

“They can come,” I said and hoisted Cyril, two legs at a time, into the boat.

Princess Arjumand promptly turned on her heel, flouncing her pretty tail in the air, and started for the fishpond.

“Oh, no you don’t,” I said and snatched her up, handed her to Verity, who was still standing up, and untied the rope.

“Sit down,” I said and cast off. Verity sat down with a thump, the cat still in her arms. I jumped in, took up the oars, and started rowing out toward the current.

By going downstream, I could get her away faster, but we’d have to go past the house and a good section of the lawn, and I didn’t want anyone to see us. I swung the boat upstream and rowed out of sight of Muchings End as rapidly as I could. There were a lot of boats on the river. One of them waved gaily to us, and Verity waved back. I rowed faster, hoping it wasn’t one of the Chattisbourne girls.

I had thought we would be safe on the river, but I had forgotten how many people went boating in the afternoon, and fishing. It was obvious we weren’t safe, and I began looking for some safe side stream or backwater we could pull into.

“I thought you said we were going to feed the ducks,” Verity said accusingly. “Lord Peter and Harriet fed the ducks.”

“We will, I promise,” I said. On the far bank lay some weeping willows whose branches dipped almost down to the water. I rowed across the river toward them.

“Do you believe in love at first sight?” Verity said. “I didn’t. And then I saw you standing there, all covered with soot — when are we going to feed the ducks?”

I rowed in under the willows, pushing against the bank with my oar to bring us round and close to the bank. We were completely hidden from the river here. The willow branches arched over us and down into the water, enclosing us in a pale-green bower. The sun shimmered through the leaves like the net as it was about to open.

I laid down the oars and looped the rope gently over a low-hanging branch. We should be safe here.

“Verity,” I said, knowing this was probably hopeless. “What did you find out in Oxford?”

She was playing with Princess Arjumand, shaking the ribbons of her hat at her.

“Did you talk to the forensics expert?” I persisted. “Has she found out who Mr. C is?”

“Yes,” she said.

“Yes,” I said. “You know who Mr. C is?”

She frowned. “No. I mean, yes, I talked to her.” She took off her hat and began untying one of the ribbons. “She said it’s got between seven and ten letters, and the last one’s an ‘N’ or an ‘M.’ ”

It wasn’t Mr. Chips then. Or Lewis Carroll.

“I told her to stop looking for references to Princess Arjumand,” Verity said, “and to concentrate on Mr. C and the date of the trip to Coventry.” She finished untying the ribbon and dangled it at Princess Arjumand.

“Good,” I said. “You said Carruthers was stuck in Coventry. Didn’t you mean the new recruit?”

“No,” she said, playing with the ribbon. The cat reared up on her hind legs and batted at it with her white paws. “They got him out. Besides, this is different.” She danced the ribbon up and down. Cyril came over to investigate.

“How is it different?” I asked patiently.

Cyril sniffed the dangling ribbon. The cat smacked him smartly on the nose and went back to the batting. “The new recruit couldn’t find the net,” she said. “It was open. Now it’s not.”

“When they try to bring Carruthers through, the net won’t open?” I said, trying to get this straight, and she nodded.

T.J. had said net failure was a worsening sign of an incongruity.

“And they’ve tried more than once?”

“They’ve tried everything,” she said, pulling the ribbon up sharply. The cat leaped for it, and the boat rocked. “T.J.’s even trying the battle of Waterloo.”

She had said something about Waterloo before, but I’d assumed it was just babblings. “What exactly is T.J. doing?” I asked.

“Changing things,” she said, holding the ribbon very still. Princess Arjumand watched her, ready to pounce. “Opening the gate at Hougoumont, bringing up D’Erlon’s troops. Did you know Napoleon had terrible handwriting? It’s worse than Tossie’s diary. No one can decipher it.”

She jerked the ribbon suddenly. Princess Arjumand leaped for it. The boat rocked. “I think he lost the battle because of his hemorrhoids.”

Whatever T.J. was doing with Waterloo, it would have to wait. It was getting late, and Verity didn’t seem to be getting appreciably better. I obviously couldn’t take her back like this, and the only thing I could think of that might help was sleep.

“He couldn’t ride with hemorrhoids,” she said. “That’s why he stayed the night at Fleurus. And that’s why he lost the battle.”

“Yes, you’re probably right,” I said. “I think you should lie down and rest.”

She continued to dangle the ribbon. “It’s terrible, really, how important a little thing like that can be. Like my saving Princess Arjumand. Who would have thought it would lose a whole war?”

“Verity,” I said firmly and took the ribbon away from her. “I want you to lie down and rest now.”

“I can’t,” she said. “I have to go steal Tossie’s diary and find out who Mr. C is and then I have to go tell Mr. Dunworthy. I have to repair the incongruity.”

“There’s plenty of time for that,” I said. “First you need to sleep.” I pulled a slightly mildewed cushion out from under the prow and placed it on the seat. “You lie down right here.”

She lay down obediently and put her head on the pillow. “Lord Peter took a nap,” she said. “Harriet watched him sleep, and that’s when she knew she was in love with him.”

She sat up again. “Of course I knew it from the second page of Strong Poison, but it took two more books for Harriet to figure it out. She kept telling herself it was all just detecting and deciphering codes and solving mysteries together, but I knew she was in love with him. He proposed in Latin. Under a bridge. After they solved the mystery. You can’t propose till after you’ve solved the mystery. That’s a law in detective novels.”