“Very well,” Joan said. “I can see why you rushed to Aspasia’s address yesterday afternoon, Tobias.” She looked at Lavinia. “But what on earth made you decide to search her house yesterday?”

“An excellent question.” Tobias gave Lavinia a dark look. “You may be assured that I asked it myself.”

“Not that he paid any attention to the answer,” Lavinia said briskly. “I vow, he would not leave the matter alone last night. It was most annoying. He carried straight on through a cold supper that I was attempting to enjoy. Eventually I was obliged to ask him quite forcefully to leave the house and come back when he was in a better mood.”

“Well?” Vale prompted. “What is the answer? Why did you go to search Aspasia’s town house?”

There was a short silence. Lavinia could feel all eyes on her. She took a sip of tea and put down her cup.

“Impulse,” she said.

Tobias looked even more grim.

“I saw Aspasia in Oxford Street yesterday,” she continued. When she alighted from her carriage I noticed her half boots, and I thought of something that Sweet Ned had said when I asked him to describe the attire of the woman who had employed him. Among other things, he mentioned that she wore a pair of low kid boots.”

“Expensive and very fashionable.” Joan’s expression brightened with understanding. “Of course. Ned told you that the woman was dressed in an old gown and you reasoned that the killer’s boots should have matched the poor quality of the rest of the clothes.”

“Not exactly. What struck me was that a male killer who wore an old, unfashionable gown to hide his gender would likely not invest in a pair of very expensive kid half boots. Indeed, when I saw the murderer in Beaumont Castle that night, he was wearing plain, sturdy leather shoes. Just the sort one would expect a housemaid to possess.”

“The sort of footwear that a man could run in, should the need arise,” Tobias added drily.

“Very clever of you,” Joan said.

“Then I noticed that Aspasia’s hair was dressed in a profusion of curls and ringlets,” Lavinia continued. “It reminded me that Sweet Ned had also mentioned that his employer’s blond wig had been done in a very simple style with a knot at the back. It suddenly made sense that someone who was not an expert hairdresser would select just such a plain design for a wig meant to be a disguise.”

“Very well,” Joan said. “That explains the impulse to stop by her house on your way home. After all, Aspasia seemed to be safely occupied in shopping.”

Lavinia made a face. “Unfortunately, she had set a pair of street lads to watch me. When they saw me head toward the street where she lived, they ran back and warned her that I was on my way to her address. She always made sure her little spies knew where to find her. She quickly followed me on foot. She saw me talk to the old man in the park and then she saw me disappear down the alley behind Number Seventeen.”

Tobias folded his arms. “At that point, Aspasia, too, acted on impulse. She realized that if Lavinia was sneaking into her house it meant that she herself was now a suspect. She understood at once that she had to get rid of Lavinia and leave the country immediately.”

“So she seized the nearest hostage and tried to use him to take me captive,” Lavinia said. “But instead of an aged, infirm old man, she chose a retired professional killer.”

“What was the Memento-Mori Man doing in the park in front of her house?” Joan asked.

“Obviously he was waiting for her to return home.” Tobias reached into his pocket and removed the death’s-head ring he had found at the top of the staircase in Aspasia’s town house. “I believe that he went there to kill her. He was no doubt the one who had the message delivered to the housekeeper inducing her to leave the house for the afternoon.”

“He was waiting for his quarry,” Vale said. “But Lavinia showed up first.”

Tobias eyed Lavinia. “She no doubt complicated matters for him, but he seemed quite tolerant about the change in his plans. His ability to adjust his strategy on the spur of the moment was no doubt one of the reasons for his professional success years ago.”

“Where do you think he is now?” Joan asked.

“On his way back to his cottage by the sea, no doubt,” Lavinia said quietly. “I suspect that he only came out of retirement to avenge the deaths of his apprentices.”

“At least that is what he would have us believe,” Tobias growled. “Personally, I would not put any credence in anything he told you, Lavinia.”

She looked at him. “He was an old man, Tobias. And unarmed, except for his walking stick. You could have chased after him and shot him dead yesterday. Why did you let him go?”

Tobias clasped his hands behind his back and gazed out the window into the park. “I think he allowed himself to be taken hostage because he knew you were in that house and Aspasia intended to murder you. His goal was to protect you. By dispatching her when he did, he may well have saved your life. I owed him something for that.”

There was a short silence while they all contemplated the admission.

After a while, Lavinia cleared her throat. “There was one other reason why I gave in to impulse yesterday and went to Aspasia’s house.”

They all waited.

“I was looking for any excuse to connect her to the murders,” Lavinia said. “I never did like that woman.”

The envelope was on the step in front of Number 7 when Tobias arrived for breakfast the next morning. A prickle of awareness tingled between his shoulders when he stooped to pick it up.

He straightened swiftly and turned, searching the street. The only person about other than himself was an elderly gardener industriously clipping a hedge at the corner. The man’s face was shielded by a broad-brimmed hat. If he noticed Tobias’s scrutiny, he gave no sign.

Tobias watched him for a while before he examined the design imprinted in the blob of black wax that sealed the letter. He smiled to himself. When he looked up again, the gardener had disappeared.

He opened the door and stepped inside the front hall.

“There you are, Mr. March.” Mrs. Chilton came toward him, wiping her hands on her apron. “I thought I heard someone on the step. “You’re just in time for breakfast.”

“I know. A stunning surprise, is it not?”

She rolled her eyes and waved him off toward the breakfast room. He went down the hall, envelope in hand, and found Lavinia and Emeline at the table in the sunny little chamber.

“Good morning, sir,” Emeline said cheerfully. “What have you got there?”

“A letter that I found just now on your front step.”

Lavinia lowered her newspaper and eyed the envelope curiously.

“On the step, you say? I wonder who left it there?”

“Why don’t you open it and solve the mystery.” Tobias took a chair and handed the package to her.

She glanced at it with absent curiosity and then uttered a tiny yelp when she saw the death’s-head imprinted in the black wax.

“The Memento-Mori Man must have left it,” she told Emeline while she unfolded the letter. “I wonder what on earth he-” She broke off when a bank draft fell onto the table. “Goodness. A thousand pounds’

“Read the letter,” Emeline said, brimming with excitement. “Hurry, please, I cannot stand the suspense.”

Tobias poured coffee for himself. “Something tells me we have just been paid our fee for the case of the Memento-Mori Man.”

Lavinia studied the elegant handwriting and read the letter aloud.

My Dear Mrs. Lake and Mr. March:

I trust the enclosed draft will cover the fees and expenses for your services in this recent affair. I apologize for the inconvenience and the danger to you both.

I am aware that you likely have some lingering questions. I shall attempt to answer them. It is the least I can do under the circumstances.