Hardcastle shrugged. "It is certainly past time… Your list appears to be a rather long one."

"It is proving difficult to know who would have had knowledge of the caves of Upper Biddleton. Every time I make inquiries at my club I discover that yet another member has taken up an interest in collecting fossils. I had no notion so many people were fascinated with old bones."

"Perhaps I can help. During my fossil collecting days I met many others who were similarly inclined. I might recognize some of the names on your list."

Gideon hesitated and then turned the list around so that his father could peruse it.

"Interesting," Hardcastle said absently as he ran his finger down the list. "I think you can remove Donnelly and Jenkins. As I recall, they rarely leave London and would certainly not go anywhere as unfashionable as Upper Biddleton. Their interest in fossils is limited."

Gideon eyed his father and then leaned forward to put a checkmark next to the names. "Very well," he said stiffly.

"Do you mind if I ask why you are so determined to catch this mystery man?"

"As soon as we return to Upper Biddleton, Harriet will head straight back to her precious caves. I want to be certain it is safe for her. I cannot be sure it is until I know that whoever was operating the ring of thieves has been apprehended. Next time she might stumble into a gang of cutthroats, not just their stolen goods."

Hardcastle's eyes were sharp. "I see. You believe this master thief will return to the caves?"

"I see no reason why he would not wish to set up another similar operation as soon as the excitement has died down. He no doubt knows I cannot stay in Upper Biddleton all the time to keep an eye on the beach. And the scheme itself worked very well until Harriet accidentally stumbled into that cavern. Yes, I think he might try it again."

Hardcastle's brows came together. "In that case, we had best get to work." He glanced at the next two names on the list. "Restonville and Shadwick both have fortunes that would make Midas blush. They would have no need to resort to running a ring of thieves."

"Very well." Gideon checked off two more names.

He and his father continued to work for several minutes, gradually shortening the list. They were midway through the task when Harriet and Lady Hardcastle breezed into the room, dressed to go out. Gideon and his father rose politely.

"Just thought we would let you know that we are going shopping, my lord," Harriet said airily. "Your mother has expressed a desire to see the latest fashions."

"I am in desperate need of a new bonnet and some fabric for one or two new gowns," Lady Hardcastle said. She gave Harriet a tentative smile.

Gideon did not miss the expression in his mother's eyes when she looked at Harriet. It occurred to him that his wife was successfully charming his mother, just as she did everyone else.

"Nothing like a shopping expedition to give two women an opportunity to get to know each other," Harriet said briskly. "Your mother and I have so much in common, my lord."

Gideon arched a brow. "Such as?"

"You, of course." Harriet grinned.

Lady Hardcastle's gaze flitted anxiously back and forth between her husband and son. "I see you two are occupied."

"Quite so," Hardcastle said. "We are going over Gideon's list of suspicious persons."

Harriet's eyes widened. "Suspicious persons?"

Gideon groaned. "I meant to warn you not to say anything about it," he growled to his father.

"What is this about suspicious persons?" Harriet demanded eagerly.

"I am looking for someone who might have organized that ring of thieves who invaded the caves," Gideon explained shortly. "I have reason to believe it is a person who is admitted to the best drawing rooms. That person must also be someone who might have had an opportunity to know about the caverns in the cliffs."

"A fossil collector, perhaps?"

Gideon nodded reluctantly. "Yes. Quite possibly."

"What a brilliant notion. Fossil collectors can be a very unscrupulous lot, as I have told you, my lord." Harriet said. Enthusiasm lit her eyes. "Mayhap I can help. I have made the acquaintance of many collectors here in London and I can think of several who strike me as a bit shady."

Gideon smiled ruefully. "You find the vast majority of your colleagues untrustworthy. I do not think your opinions would help us narrow the list much. Nevertheless, you can give me the names of the members of your Fossils and Antiquities Society. I can compare it to my lists."

"Certainly. I shall work on it as soon as we return from shopping."

Lady Hardcastle glanced at her husband. "Who is on the list thus far?"

"Several people. It is quite a long list," Hardcastle said.

"May I see it?" Lady Hardcastle floated over to the desk.

Harriet followed and peered over her shoulder. "My goodness. How will you ever find the culprit among all those suspicious persons?"

"It will not be easy," Gideon said. "I suggest you and my mother be on your way, madam. My father and I have work to do."

Lady Hardcastle was frowning over the list. "I do not see Bryce Morland's name on here. He was never interested in fossils, as I recall, but he certainly knew the terrain around Upper Biddleton."

Gideon met his mother's questioning gaze. "I have considered the possibility that Morland was behind it. He would certainly have no scruples about turning to theft. But I do not think it was him. In the event it was, we have nothing to worry about. He has left the country."

"Quite true." Lady Hardcastle continued to peruse the list. "What about Clive Rushton? I do not see his name, either. He was an avid collector at one time." She looked at Hardcastle. "As I recall, he was the one who introduced you to the hobby, my dear."

There was an acute silence. Hardcastle shifted uneasily in his chair. "The man was my rector. Hardly the sort to operate a ring of thieves."

Gideon sat down slowly. He gazed thoughtfully at his mother. "I put his name on the list initially, but removed it when I realized he was not showing up on very many of the guest lists of houses that were eventually robbed. That was one of the reasons I removed Morland's name, too. The man I am after is invited into the most exclusive homes of the ton. Rushton and Morland did not move in those circles."

"Heavens, that does not signify," Lady Hardcastle said lightly. "The best homes are filled to the rafters with people on the night of a large soiree or ball. The affair would be counted a failure if everyone did not proclaim the event an absolute crush. It is true one is supposed to present one's invitation at the door, but you know how it is. The front steps and hallways are packed at such times. One could slip past."

"Your mother is right, my lord," Harriet said quickly.

"Why, if one is properly dressed and appears to be in the company of someone else who was invited, it would be simple to slip into a crowded ballroom. Who would notice one extra guest in the crush?"

Gideon drummed his fingers on his desk. "You may have a point."

Hardcastle appeared much struck by the notion. "Damme if they do not. Why, one could even wait until the crowd was at its height and then enter from the garden. No one would notice."

"If that is the case," Gideon said, thinking swiftly, "then Rushton is still a viable candidate. So is Morland. Damnation, so are a great many others."

Hardcastle held up a palm. "There is still the fact that whoever masterminded the ring of thieves had to be very familiar with the caves of Upper Biddleton. That will keep the list from growing too long."

"Yes. I suppose so."

"Feel free to call upon Harriet and myself if you need further guidance in the ways of Society." Lady Hardcastle smiled as she tugged on her gloves. "Come along, Harriet. We must be on our way. I am eager to walk down Oxford Street again. There used to be a little French milliner there who created the most exquisite bonnets."