After she had laid the lodger's breakfast on the table she prepared
to leave the room. "I suppose I'm not to do your room till you goes
out, sir?"

And Mr. Sleuth looked up sharply. "No, no!" he said. "I never
want my room done when I am engaged in studying the Scriptures, Mrs.
Bunting. But I am not going out to-day. I shall be carrying out a
somewhat elaborate experiment--upstairs. If I go out at all" he
waited a moment, and again he looked at her fixedly "--I shall wait
till night-time to do so." And then, coming back to the matter in
hand, he added hastily, "Perhaps you could do my room when I go
upstairs, about five o'clock--if that time is convenient to you,
that is?"

"Oh, yes, sir! That'll do nicely!"

Mrs. Bunting went downstairs, and as she did so she took herself
wordlessly, ruthlessly to task, but she did not face--even in her
inmost heart--the strange tenors and tremors which had so shaken
her. She only repeated to herself again and again, "I've got upset
--that's what I've done," and then she spoke aloud, "I must get
myself a dose at the chemist's next time I'm out. That's what I
must do."

And just as she murmured the word "do," there came a loud double
knock on the front door.

It was only the postman's knock, but the postman was an unfamiliar
visitor in that house, and Mrs. Bunting started violently. She was