There was something about the corner house mystery that gripped the public imagination. There was about it both the realism and the romance that always go to make up a popular sensation.

In the first place, the corner house was already marked as the scene of one unsolved tragedy. For years it had been shut up, for years the boys of the locality had challenged one another to go down the area steps after dark, for years nobody had crossed the threshold. Then the door had been left open for the public eye to look on another tragedy.

The victim was no ordinary man either. People flocked to view the body as morbid folks will do on such occasions. The victim of the crime was no more attractive in death than he had been in life. There were the crooked limbs, the hideous hooked nose, the claws with the orange splashes on them.

But nobody identified the dead man; the police had not expected anything of the kind. The inquest had been formally opened at the corner house, and at the suggestion of Sergeant Prout, who had the case in hand, was adjourned for a fortnight. It was hard to get the people out of the house afterwards.

They were gone out at last, and Sergeant Prout was left to make his investigations in peace. Up to now he had hardly as much as examined the body. An attempt had been made to find the owner of the house, or the agents, but without success.

"It\'s a queer thing," said Prout, scratching his snaky little head reflectively; "a very queer thing. Now here\'s a house for you. Given a man of energy and pluck who has learnt its story, and what is to prevent his taking possession and living here as if the place was his own? He comes and picks the lock, he has his servants in, and gives out that he is Jones or Robinson, and there\'s an end of it so long as he holds his head high and pays his creditors. Of course there is the risk of the real man turning up, but criminals must always take chances. In a way that\'s what happened. The poor fellow was lured here to be murdered by some one who pretended that the house was his. It\'s a very pretty case."

It was a puzzling one, too. Every policeman who had been on night duty in Lytton Avenue for months was closely examined. Once or twice a night the doors of the house had been tried without effect. Nobody had ever been seen to come away or enter. No suspicious characters had been seen loafing about. Not one of the officers had ever seen a light in the place.

"I\'ll go and look at the gas meter," said Prout.

He was an efficient officer in his way, only, like most members of the force, he lacked imagination. Give him something to work on, and there was not a more efficient detective in New Scotland Yard. But there was no clue here, so he had to fall back on the old familiar methods.

Here was the gas meter under the stairs as usual. Behind it was the grimy, dirty card, which showed no entry for years. It was marked "taken 5 Feb.," in other words the meter had been read the day the owner had disappeared. By reading the index Prout saw that a hundred odd cubic feet of gas had been used since.

Here was something to go upon. Beyond doubt that gas had been used lately. Prout made a careful examination of the burners, sniffing and blowing at all of them. He found out one thing, only the burners in the hall and the bedroom where the murdered man had been found had been used for a long time. In a bedroom at the top of the house was a paraffin lamp with quite a new wick in it. With a stump of pencil Prout made a rapid calculation on the wall-paper.

"Lamp used by murderer waiting for his victim," he deduced. "Did not want any more li............