key turned once more, and all was silence. Holmes twitched my sleeve, and together we stole down the stair.
“I will call again in the evening,” said he to the expectant landlady. “I think, Watson, we can discuss this business better in our own quarters.”
“My surmise, as you saw, proved to be correct,” said he, speaking from the depths of his easy-chair. “There has been a substitution of lodgers. What I did not foresee is that we should find a woman, and no ordinary woman, Watson.”
“She saw us.”
“Well, she saw something to alarm her. That is certain. The general sequence of events is pretty clear, is it not? A couple seek refuge in London from a very terrible and instant danger. The measure of that danger is the rigour of their precautions. The man, who has some work which he must do, desires to leave the woman in absolute safety while he does it. It is not an easy problem, but he solved it in an original fashion, and so effectively that her presence was not even known to the landlady who supplies her with food. The printed messages, as is now evident, were to prevent her sex being discovered by her writing. The man cannot come near the woman, or he will guide their enemies to her. Since he cannot communicate with her direct, he
