And then—­and then, in a sort of way, Mrs. Bunting had become attached to Mr. Sleuth.  A wan smile would sometimes light up his sad face when he saw her come in with one of his meals, and when this happened Mrs. Bunting felt pleased—­pleased and vaguely touched.  In between those—­those dreadful events outside, which filled her with such suspicion, such anguish and such suspense, she never felt any fear, only pity, for Mr. Sleuth.

Often and often, when lying wide awake at night, she turned over the strange problem in her mind.  After all, the lodger must have lived somewhere during his forty-odd years of life.  She did not even know if Mr. Sleuth had any brothers or sisters; friends she knew he had none.  But, however odd and eccentric he was, he had evidently, or so she supposed, led a quiet, undistinguished kind of life, till—­till now.

What had made him alter all of a sudden—­if, that is, he had altered?  That was what Mrs. Bunting was always debating fitfully with herself; and, what was more, and very terribly, to the point, having altered, why should he not in time go back to what he evidently had been—­that is, a blameless, quiet gentleman?

If only he would!  If only he would!

As she stood in the hall, cooling her hot forehead, all these thoughts, these hopes and fears, jostled at lightning speed through her brain.

She remembered what young Chandler had said the other day—­that there had never been, in the history of the world, so strange a murderer as The Avenger had proved himself to be.

She and Bunting, aye, and little Daisy too, had hung, fascinated, on Joe’s words, as he had told them of other famous series of murders which had taken place in the past, not only in England but abroad—­especially abroad.

One woman, whom all the people round her believed to be a kind, respectable soul, had poisoned no fewer than fifteen people in order to get their insurance money.  Then there had been the terrible tale of an apparently respectable, contented innkeeper and his wife, who, living at the entrance to a wood, killed all those humble travellers who took shelter under their roof, simply for their clothes, and any valuables they possessed.  But in all those stories the murderer or murderers always had a very strong motive, the motive being, in almost every case, a wicked lust for gold.

At last, after having passed her handkerchief over her forehead, she went into the room where Bunting was sitting smoking his pipe.

“The fog’s lifting a bit,” she said in an ill-assured voice.  “I hope that by this time Daisy and that Joe Chandler are right out of it.”

But the other shook his head silently.  “No such luck!” he said briefly.  “You don’t know what it’s like in Hyde Park, Ellen.  I expect ’twill soon be just as heavy here as ’twas half an hour ago!”

She wandered over to the window, and pulled the curtain back.  “Quite a lot of people have come out, anyway,” she observed.