“It isn’t safe for decent folk to be out in such weather—­no, that it ain’t, not unless they have something to do that won’t wait till to-morrow.”  The speaker was looking straight into his wife’s narrow, colourless face.  Bunting was an obstinate man, and liked to prove himself right.  “I’ve a good mind to speak to him about it, that I have!  He ought to be told that it isn’t safe—­not for the sort of man he is—­to be wandering about the streets at night.  I read you out the accidents in Lloyd’s—­shocking, they were, and all brought about by the fog!  And then, that horrid monster ’ull soon be at his work again—­”

“Monster?” repeated Mrs. Bunting absently.

She was trying to hear the lodger’s footsteps overhead.  She was very curious to know whether he had gone into his nice sitting-room, or straight upstairs, to that cold experiment-room, as he now always called it.

But her husband went on as if he had not heard her, and she gave up trying to listen to what was going on above.

“It wouldn’t be very pleasant to run up against such a party as that in the fog, eh, Ellen?” He spoke as if the notion had a certain pleasant thrill in it after all.

“What stuff you do talk!” said Mrs. Bunting sharply.  And then she got up.  Her husband’s remarks had disturbed her.  Why couldn’t they talk of something pleasant when they did have a quiet bit of time together?

Bunting looked down again at his paper, and she moved quietly about the room.  Very soon it would be time for supper, and to-night she was going to cook her husband a nice piece of toasted cheese.  That fortunate man, as she was fond of telling him, with mingled contempt and envy, had the digestion of an ostrich, and yet he was rather fanciful, as gentlemen’s servants who have lived in good places often are.

Yes, Bunting was very lucky in the matter of his digestion.  Mrs. Bunting prided herself on having a nice mind, and she would never have allowed an unrefined word—­such a word as “stomach,” for instance, to say nothing of an even plainer term—­to pass her lips, except, of course, to a doctor in a sick-room.

Mr. Sleuth’s landlady did not go down at once into her cold kitchen; instead, with a sudden furtive movement, she opened the door leading into her bedroom, and then, closing the door quietly, stepped back into the darkness, and stood motionless, listening.

At first she heard nothing, but gradually there stole on her listening ears the sound of someone moving softly about in the room just overhead, that is, in Mr. Sleuth’s bedroom.  But, try as she might, it was impossible for her to guess what the lodger was doing.

At last she heard him open the door leading out on the little landing.  She could hear the stairs creaking.  That meant, no doubt, that Mr. Sleuth would pass the rest of the evening in the cheerless room above.  He hadn’t spent any time up there for quite a long while—­in fact, not for nearly ten days.  ’Twas odd he chose to-night, when it was so foggy, to carry out an experiment.