"Your statement is most interesting," said Sherlock Holmes. "Has anything else occurred to you?"
"Yes; and no later than to-day. That is why I have come to you. This morning I received this letter, which you will perhaps read for yourself."
"Thank you," said Holmes. "The envelope, too, please. Postmark, London, S.W., date, July 7. Hum! Man's thumb-mark on corner—probably postman. Best quality paper. Envelopes at sixpence a packet. Particular man in his stationery. No address. 'Be at the third pillar from the left outside the Lyceum Theatre to-night at seven o'clock. If you are distrustful, bring two friends. You are a wronged woman, and shall have justice. Do not bring police. If you do, all will be in vain. Your unknown friend.' Well, really, this is a very pretty little mystery. What do you intend to do, Miss Morstan?"
"That is exactly what I want to ask you."
"Then we shall most certainly go. You and I and—yes, why, Doctor Watson is the very man. Your correspondent says two friends. He and I have worked together before."
"But would he come?" she asked, with something appealing in her voice and expression.
"I should be proud and happy," said I, fervently, "if I can be of any service."
"You are both very kind," she answered. "I have led a retired life, and have no friends whom I could appeal to. If I am here at six it will do, I suppose?"
"You must not be later," said Holmes. "There is one other point, however. Is this handwriting the same as that upon the pearl-box addresses?"
"I have them here," she answered, producing half a dozen pieces of paper.