I pointed to one of the two trays on the small table near the door. “That’s where all the letters go that are written by Dr. Murray and Da and all the others. Sometimes I get to put them in the pillar box at the end of the day,” I said. “The letters you send to Dr. Murray go in this tray. If they have slips in them we take them out first, and Da lets me put them into pigeon-holes.”

Ditte rummaged around in her handbag and produced one of the small envelopes I knew so well. Even with her there beside me, the neat and familiar slant of her writing brought a tiny thrill.

“Thought I’d save the cost of a stamp,” she said, handing me the envelope.

I wasn’t sure what to do with it without Da giving directions.

“Are there slips inside?” I asked.

“No slips, just my opinion on the inclusion of an old word that has the gentlemen of the Philological Society a little flustered.”

“What is the word?” I asked.

She paused, bit her lip. “It’s not for polite company, I’m afraid. Your father would not thank me for introducing you to it.”

“Are you asking Dr. Murray to leave it out?”

“On the contrary, my darling, I’m urging him to put it in.”

I placed the envelope on top of the pile of letters on Dr. Murray’s desk and continued with my tour.

“These are the pigeon-holes that hold all the slips,” I said, waving my arm up and down the nearest wall of pigeon-holes, then doing the same for other walls around the Scriptorium. “Da said there would be thousands and thousands of slips and so there needed to be hundreds and hundreds of pigeon-holes. They were built especially, and Dr. Murray designed the slips to be the perfect fit.”

Ditte removed a bundle, and I felt my heart beat. “I’m not supposed to touch the slips without Da,” I said.

“Well, I think if we’re very careful, no one will know.” Ditte gave me a secret smile, and my heart beat faster. She flicked through the slips until she came to an odd one, larger than the rest. “Look,” she said, “it’s written on the back of a letter—see, the paper is the same colour as your bluebells.”

“What does the letter say?”

Ditte read what she could. “It’s just a fragment, but I think it might have been a love letter.”

“Why would someone cut up a love letter?”

“I can only assume the sentiment was not returned.”

She put the slips back in their pigeon-hole and there was nothing to show that they had ever been removed.