She's back! Miss Mary Wilcox – who one reviewer kindly called 'the most despicable villain in all of Holmesworld - returns from the excitement in Cornwall (see 'The Mystery of the Cornish Legend'). So Holmes and Watson are clearly on shaky ground … Holmes, Watson and Clay are creations of ACD, Gibson, Cromwell and (worryingly) Miss Wilcox are mine.

A Journey with Miss Wilcox

"Good morning, Miss Wilcox," said Holmes softly.

"Charmed, I'm sure," she replied. "Come on, let's be getting you out of here." The crossbow she held was directed at one of Clay's associates, who was backing off into the corner of the room along with the others; all unsure of their next move and quite uncertain as to how to deal with the woman who had quietly followed the up the stairs. Clay was still lying on the ground, groaning softly as blood trickled from the wound on his head where Miss Wilcox had struck him. She tucked the truncheon into her belt.

"I'm sorry," interrupted Watson, "but am I missing something here? In Portsmouth you were going to shoot us and then blow up the boat, in Cornwall you were going to drown the one you didn't shoot with that blasted crossbow; and now you're helping us?"

"Oh, Doctor," she breathed. "Please do not consider for a moment that I am helping you for altruistic purposes. It's just that I consider Mr. Clay here to be an unworthy opponent for you. I couldn't have him spoiling my fun."

"And what fun might that be?" replied Holmes as they made their way to the stairs.

"I have plans, Mr. Holmes," she replied. "That's all you need to know. I won't make the mistake of telling you too much – I know you too well."

"Watson's accounts do sometimes err too much on the side of praise. But I've told you that before of course."

"I am sure you deserve every approbation."

Watson shook his head, as though trying to dislodge something from his ear. It was like listening in on a lovers' tryst.

Outside in the street a hansom was waiting. She beckoned them to get into it, and then she herself got into the driving seat. They set off at a fair pace through the back streets of Southwark.

"I do hope Mr. Clay is alright," she called back to them.

"I'm sure he will live," replied Holmes. "How did he find out about the White Powder?"

"It was Gibson," she replied. "I dare say you know he took the blame for one of my little schemes in Kent?"

"I saw it in Mr. Cromwell's notes," said Holmes, "although that's not quite how he described it. He spoke of a lady he encountered during his time with Lord and Lady Hevellyn who had been abandoned by a lover and was with child. He helped her after she had lost everything, but she then accused him of a crime of which he was innocent. She then disappeared and the case was dropped."

"There are many gaps in your knowledge of me, I see," she replied, "but yes I was that lady. As to the White Powder, yes, you've probably guessed – or should I say deduced, and that probably from the overpowering smell - that it was the last of the 'Olive' shipment. I told Gibson about it a couple of years back, but he must have told Clay." She sighed. "Seems like another lifetime ago since we were having our fun in Portsmouth."

Holmes ignored her. "Who was the father of your child?"

"You wouldn't believe me if I told you."

"Try me."

"Now, now, Mr. Holmes, the gentleman doth enquire too much methinks - if you will excuse the Hamlet paraphrase. But really, a lady must have her secrets from her admirers."

"I would not have classed myself as that," he replied flatly.

"Not even on a professional level?"

"Stop playing games, Miss Wilcox. What are you going to do with us?"

"We are going to pay a visit to Mr. Gibson."

"I thought he might be involved. How do you know him?"

She paused, as if thinking whether to speak. "Later. Now please, a little quiet as I need to think."

Holmes whispered to Watson, "Thoughts?"

"I don't trust her."

"Let me start again. Thoughts that surprise me."

"What is the link with Gibson? He is obviously working with Clay, but there seems a link with Miss Wilcox. They have known each other for a couple of years at least, since that business in Kent. Why should he cover her misdemeanour?"

Holmes smiled. "Very well done, Watson," he said. "There is clearly more to their relationship than she is willing to tell. We may be able to use it to our advantage."

"You still think we are in danger?"

"Of course. A leopard does not change its spots, my dear fellow. I think we are only safe for as long as we are useful to Miss Wilcox."

"But she does seem different somehow."

Holmes cast a glance at his friend. "Ever the romantic," he whispered. "I think she holds her heart close to her, Watson. I think it has been touched rarely by the warm spring of love. Twice, maybe three times perhaps – Franks, who we met in Portsmouth; young Falconer in Cornwall; and whoever is the father of her child." He spoke wistfully. "She prefers the autumn now, I think. But she is different, I agree - hardened somewhat – do you not find it interesting that she does not refer to the child? I do not think she takes a maternal interest."

"She has not had the opportunity?"

"No," he replied thoughtfully. "There is a sadness there. I think she had to give the child up. But it is too late now, she has moved on, past regrets. But who knows, perhaps the child will have an influence on her at some future point."

"I can't see how. The child probably doesn't even know its mother exists."

"Perhaps," replied Holmes. "But, see, we are here I think."

The hansom slowed to a halt outside an unlit town house. "We are here, gentlemen," she said. "Please, if you would now follow me."

"Union Street," mused Holmes, almost under his breath. "Yes, that tallies."

"With what, Holmes?" asked Watson.

"Always do your homework," he smiled. "This is Gibson's family home."

Miss Wilcox went up to the door and knocked three times. After a short wait, the sound of bolts being drawn back echoed through the night. A church clock struck two. A dark lantern was uncovered, revealing the unshaven and tired face of Gibson. Seeing Mary Wilcox, he opened the door further and ushered them in. The door was bolted behind them.

They were led into a back room. Uncovering the lantern again, it was shown to be simply furnished, with no carpet and one poor quality picture hanging on the wall above a mantelpiece whose fire had not seen heat in many months. It smelled of damp.

"Good, we are all here," said Miss Wilcox. "Mr. Holmes, I need you to witness what is about to pass."

"And that is …?"

"Gibson has been writing a full account of his dealings with Mr. Clay," she replied. "I think you will be able to use this to clip his wings somewhat."

"And why has Mr. Gibson been willing to do this?" asked Holmes. "Does he hope to avoid my censure for his role in the death of Silas Cromwell?"

Gibson started. "What!" he exclaimed to Miss Wilcox. "You knew? You didn't tell me. What did he die of?"

"Suicide," interrupted Holmes. "He shot himself after finding that he had been fooled into signing away his inheritance and a large part of the cash belonging to the estate. By you."

"No!" shouted Gibson. "It was Clay! Clay said that it would be alright, and that the money and the estate would be his without fuss."

"But who do you think Clay was working for?" pressed Holmes.

"Well … himself of course," Gibson replied. "He runs things now that Moriarty and Moran are gone."

Holmes raised himself to his full height. "You are mistaken," he said calmly. "Clay was working for Miss Wilcox."

Gibson stared in shock. "You never told me," he said to her simply.

"Why should she?" said Watson. "I don't follow."

"You don't see?" Holmes replied. "Gibson is Miss Wilcox's brother."