At last I made myself understood. Margaret’s face crumpled and she began to cry, great shuddering sobs that shook her entire body. Louise put her arms around her sister but said nothing, for she knew I was right. Margaret grasped on to the magic of novels because they held out hope that Mary-and she herself-might yet have a chance at marriage. While my own experience of life was limited, I knew such a thing would not happen. It hurt, but the truth often does.

“It’s not fair,” Margaret gasped as her sobs finally subsided. “He shouldn’t have paid her the attention he did. Spending so much time with her and complimenting her, giving her the locket and kissing her-”

“He kissed her?” A dart of the jealousy I was trying so hard to hide even from myself shot through me.

Margaret looked chastened. “I wasn’t meant to tell you! I wasn’t meant to tell anyone! Please don’t say anything. Mary only told me because-well, it’s just so delicious to talk it over with someone. It’s as if you relive the moment.” She fell silent, doubtless thinking about her own past kisses.

“I wouldn’t know about that,” I said, trying to limit the acid in my voice.

I did not sleep well that night. I was not used to having the power to affect someone’s life so, and did not easily carry its weight, as a man might have done.

The next day, before taking the letter to Coombe Street to be posted, I added Colonel Birch’s address to it. For all my arguments with Margaret against encouraging a continued link between Colonel Birch and Mary, I could not in the end act as if I were God, but had to let Molly Anning write what she would to him.

The postmistress glanced at the letter, then at me, her eyebrows raised, and I had to turn away before she could say anything. I am sure by the afternoon the gossip had gone all around town that desperate Miss Philpot had written to that cad Colonel Birch.

The Annings waited for an answer, but they received no letter.

I hoped that would be the end of our dealings with Colonel Birch, and that we would never see him again. He had his fossils-apart from the dapedium I would not send him-and could move on to another collecting fashion, such as insects or minerals. That is what gentlemen like Colonel Birch do.

It had never occurred to me that I might run into him in London. As Molly Anning had said, it is not Lyme. One million people lived in London compared to the 2000 in Lyme, and I rarely went to Chelsea, where I knew he lived, except to accompany Louise on her annual pilgrimage to the Physic Garden there. I never expected the tide would turn up two such different pebbles side by side.

We took our annual trip to London in the spring, eager to escape Lyme for a time, to see our family and make the usual rounds of visits to friends, shops, galleries and the-?flatres. When the weather was not good we often went to the British Museum, housed in Montague Mansion close to our brother’s house. Having regularly visited since we were children, we knew the collection intimately.

One particularly rainy day we had separated and were each in different rooms, with our own favourite exhibits. Margaret was in the Gallery, hovering over a collection of cameos and sealstones, while Louise was in the Upper Floor with Mary Delany’s exquisite florilegium, a collection of pictures of plants made of cut paper. I was in the Saloon, where the Natural History collection ranged over several rooms-mostly displays of rocks and minerals, but now with four rooms of fossils that had recently been rearranged and added to. There were a fair number of specimens from the Lyme area, including a few more fish that I had donated.

Mary’s first ichthyosaurus was also there, displayed in a long glass case of its own, thankfully without waistcoat or monocle, though there were still traces of plaster of Paris here and there on the specimen, the tail was still straight, and Lord Henley’s name was still attached. I had already visited it several times, and written to the Annings to describe its new position.

It was quiet in the room, with just one other party of visitors wandering amongst the cases. I was studying the skull identified by Cuvier as a mammoth when I heard a familiar voice ringing out across the room. “Dear lady, once you have seen this ichthyosaurus you will understand just how superior my own specimen is.” I closed my eyes for a moment to still my heart.

Colonel Birch had entered by the far door, dressed as usual in his outdated red soldier’s coat, while a lady a bit older than I held his arm and walked alongside. From her sombre dress it seemed she was a widow. She wore a fixed, pleasant expression, and was one of those rare people who lead with no feature whatsoever.

I froze as the two went over to Mary’s ichthyosaurus. Though close to them, my back was turned, and Colonel Birch did not notice me. I heard all of their conversation-or rather, all that Colonel Birch said, for his companion added little except to agree with him.

“Do you see what a jumble of bones this is compared to mine?” he declared. “How the vertebrae and ribs have been squeezed into a mass? And how incomplete it is? Look, do you see the discoloured plaster of Paris, in the ribs there, and along the spine? That is where Mr Bullock filled it in. Mine, however, needs no filling in. It may be smaller than this one, but I found it intact, not a bone out of place.”

“How fascinating,” the widow murmured.

“And to think they thought this was a crocodile. I never did, of course. I always knew it was something different, and that I must find one myself.”

“Of course you did.”

“These ichthyosauri are some of the most important scientific finds ever.”

“Are they?”

“As far as we know, no ichthyosaurus exists now, and has not done for some time. This means, dear lady, that learned men are charged with discovering how these creatures died out.”

“What do they think?”

“Some have suggested they died in Noah’s Flood; others that some other sort of catastrophe killed them, like a volcano or an earthquake. Whatever the cause, their existence affects our knowledge of the age of the world. We think it may be older than the 6000 years Bishop Ussher allotted it.”

“I see. How interesting.” The widow’s voice trembled a little, as if Colonel Birch’s suggestions disturbed her ordered thoughts, which were clearly slight and not used to being challenged.

“I have been reading about Cuvier’s Doctrine of Catastrophes,” Colonel Birch continued, showing off his knowledge. “Cuvier suggests that the world has been shaped over time by a series of terrible disasters, violence on such a great scale that it has created mountains and blasted seas and killed off species. Cuvier himself did not mention God’s hand in this, though others have interpreted these catastrophes as systematic-God’s regulation over His creation. The Flood would be simply the most recent of these events-which does make one wonder if another is on its way!”

“One does wonder,” the widow said in a small voice, her uncertainty making me grit my teeth. For all he annoyed me, Colonel Birch was curious about the world. If I were at his side I would have said more than “One does wonder.”

I might have kept my back to them and let Colonel Birch pass forever from our lives, but for what he said next. He couldn’t resist boasting. “Seeing all of these specimens reminds me of last summer in Lyme Regis. I grew rather good at hunting fossils, you see. Not just the complete ichthyosaurus, but fragments of many others, and a large collection of pentacrinites-the sea lilies I showed you, do you remember?”

“I’m not sure.”

Colonel Birch chuckled. “Of course not, dear lady. Ladies are not equipped to look at such things so carefully as men.”

I turned around. “I should like Mary Anning to hear you say that, Colonel Birch! She would not so easily agree, I think.”