Willie threw the door open, startling Iris. Before she could recover, he grabbed the vacant chair, spun it around, and sat down, with his arms resting on the back.

"Mister William, sir!" the maid exclaimed. "What are you doing here?"

"I want the papers you stole. Your cooperation could very well mean the difference between serving time for theft and being charged with high treason."

"Treason!" Iris put her hands to her mouth.

"Isn't that a little harsh, William?" Lucy said, wafting behind Iris and putting a hand on her shoulder. "Treason might be a difficult charge to sustain. You'd need two witnesses to the incriminating act, after all."

"I think we have two witnesses. Of course, you might be right." He paused for dramatic effect. "On the other hand, espionage is a capital crime too, and one with a much lower burden of proof than treason. I'm sure Iris will hang one way or another."

"You're scaring the poor girl. William."

"Only with the truth, my dear." Lucy and Willie continued to play off each other.

"I'm innocent!" Iris exclaimed.

"Don't even try that," Willie said with evident disgust. "All I want to know is who the man was."

"Missus Montverre doesn't allow us to have men, sir. You know that!"

"And you disobeyed," Willie replied. "But that isn't criminal. Being a spy, now, that is criminal. Spies deserve only to hang."

"I'm not a spy!" Iris pleaded.

"Perhaps she's telling the truth, William," Lucy said.

"I suppose she might," Willie replied with evident reluctance. "Maybe she's merely a dupe. But if she is, then it would oblige her to be more forthcoming."

"I don't understand what you want, sir." Iris said.

"It is very simple. Merely tell me who the man is, and where we can find him and the documents you gave to him."

Willie contemplated the maid. She did not seem particularly well educated. He wondered how much she knew of the latest technological advances in criminal investigation. Willie himself only knew what was in the paper, but somehow he doubted Iris would know even that much.

"We have your fingerprints," he said in a sudden tangent. "You touched the documents, and we have some of them. Everything you touched, we can prove."

"But I wore gloves!" she replied. Willie exchanged a shark-like grin with Lucy, who still stood behind Iris. Lucy leaned forward.

"You wore gloves when you did what, exactly?" she asked in a honeyed tone. Willie could tell that Iris had suddenly realized she'd said too much.

"I—I…" Iris stuttered. She looked down and whispered something.

"What was that?" Willie asked.

"Peter," she repeated. "That's his name. Peter Miller." Now that she had begun to talk, Iris continued to explain without prompting how she met the man, where she met him and why she did as he bid. Willie took notes but did not interrupt other than to ask her to repeat an occasional name or address. Lucy merely listened. Eventually they were interrupted by a knock on the door, and Mr. Melas indicated they should step outside. Lucy and Willie were led back to the visiting room, where they found the fat man sitting in his chair.

"Good work, my boy," Willie was told. "We will continue to hunt for this man. Unfortunately the prospects are not good."

"How so, sir?"

"Think upon it. We have chased the man from his home, but London is a city of millions. We can keep watch on a few places – ships leaving for the continent, or the German Embassy – but we cannot intercept everything. If he decides to mail the remaining papers to Germany we would have no chance of interception. Of course that is a rather low probability. There is a greater risk he will attempt to cross the Channel through a rented boat of some type which we would find more difficult to keep track of."

"What can we do?" Willie asked, aghast.

"We are not out of options," M replied. "Does nothing occur to either one of you?"

"Excuse me, Mr. Holmes," Lucy asked. "Did you discover if that book I handed over to you was, in fact, being used as some form of cipher?"

"As a matter of fact we did, and indeed it is a key to a German espionage code."

"Then perhaps we could put a code in the paper asking this Peter Miller to meet somewhere?" Lucy suggested.

"To read that code he needs this book," Willie said thoughtfully. "And we have his copy. He would need to get an exact replica to continue, wouldn't he? Wouldn't that edition be relatively difficult to acquire in London?"

"There is a market here for German literature," M replied. "But you are correct in surmising he would need to get a copy of this exact edition, from a Berlin publisher. There are three stores in the Greater London area that might carry it."

"Perhaps we can begin there," Willie suggested. "Either he will show up, in which case we can follow him, or he's been there and gone, and we might find a lead. If neither plan works, we go to Lucy's plan and try a lure." Willie smiled at her.

"That is eminently sensible. We will proceed accordingly." With this pronouncement the fat man dismissed them.

Outside the Diogenes Club Willie waited with Lucy for Mrs. Melas and a cab to reappear.

"Lucy," he said. "This will sound terrible but – why did you come?"

"I told you. Mrs. Melas invited me."

"Yes, but—" He was interrupted by her laugh.

"You want to catch this spy to protect your family's reputation. As you know, my parents currently find you more than acceptable. But that would change if your family were disgraced. So it is in my own interest to keep you eligible. Assuming, of course, you have honorable intentions." She smiled, and he blushed before taking her hand and kissing it.

"My dear Lucy, if your parents do favor me, then I wish to do nothing that might dissuade them."