While these thoughts galloped disconnectedly through her mind, Mrs. Bunting went on with her cooking, preparing the cheese, cutting it up into little shreds, carefully measuring out the butter, doing everything, as was always her way, with a certain delicate and cleanly precision.

And then, while in the middle of toasting the bread on which was to be poured the melted cheese, she suddenly heard sounds which startled her, made her feel uncomfortable.

Shuffling, hesitating steps were creaking down the house.

She looked up and listened.

Surely the lodger was not going out again into the cold and foggy night—­going out, as he had done the other evening, for a second time?  But no; the sounds she heard, the sounds of now familiar footsteps, did not continue down the passage leading to the front door.

Instead—­Why, what was this she heard now?  She began to listen so intently that the bread she was holding at the end of the toasting-fork grew quite black.  With a start she became aware that this was so, and she frowned, vexed with herself.  That came of not attending to one’s work.

Mr. Sleuth was evidently about to do what he had never yet done.  He was coming down into the kitchen.

Nearer and nearer came the thudding sounds, treading heavily on the kitchen stairs, and Mrs. Bunting’s heart began to beat as if in response.  She put out the flame of the gas-ring, unheedful of the fact that the cheese would stiffen and spoil in the cold air.

Then she turned and faced the door.

There came a fumbling at the handle, and a moment later the door opened, and revealed, as she had at once known and feared it would do, the lodger.

Mr. Sleuth looked even odder than usual.  He was clad in a plaid dressing-gown, which she had never seen him wear before, though she knew that he had purchased it not long after his arrival.  In his hand was a lighted candle.

When he saw the kitchen all lighted up, and the woman standing in it, the lodger looked inexplicably taken aback, almost aghast.

“Yes, sir?  What can I do for you, sir?  I hope you didn’t ring, sir?”

Mrs. Bunting held her ground in front of the stove.  Mr. Sleuth had no business to come like this into her kitchen, and she intended to let him know that such was her view.

“No, I—­I didn’t ring,” he stammered awkwardly.  “The truth is, I didn’t know you were here, Mrs. Bunting.  Please excuse my costume.  My gas-stove has gone wrong, or, rather, that shilling-in-the-slot arrangement has done so.  So I came down to see if you had a gas-stove.  I am going to ask you to allow me to use it to-night for an important experiment I wish to make.”

Mrs. Bunting’s heart was beating quickly—­quickly.  She felt horribly troubled, unnaturally so.  Why couldn’t Mr. Sleuth’s experiment wait till the morning?  She stared at him dubiously, but there was that in his face that made her at once afraid and pitiful.  It was a wild, eager, imploring look.