He sat on the grassy bank for a long time, trying to get back his strength and wondering what he had best do next.  All was silent around him, saving for the hooting of some owls and the occasional far-off cry of a whip-poor-will.  He gazed around, but not a light was in sight.  The old mill was beyond him, partly screened by a number of trees.

Should he return to the vicinity of Matlock Styles’ house and set a watch?  This he thought a good idea, but there were two objections.  He was wet to the skin and wanted some dry clothes, and he did not relish running into one or more of the Englishman’s savage dogs, when he had nothing with which to defend himself.

As he sat there meditating, a stream of light shot across his feet and then disappeared.  It had come from an upper window of the old mill and he scrambled to his feet to see what it meant.  In a moment more he saw another stream of light and then a curious white cloud floated up from another window of the mill.  At the same time he heard loud groans and then a hoarse note coming from what appeared to him to be a fog horn.  The groans and the white vapor lasted for several minutes and then died away together.

It was a most uncanny happening and made his heart beat a little quicker than was its usual habit.  Then of a sudden his face brightened and he smiled to himself.

“Make-believe ghosts and nothing more,” he mused.  “I wonder who is trying to scare folks away from the old mill?  Most likely it is this Matlock Styles and it is part of another game of his.  He must have gotten his idea from the old miser in the ‘Chimes of Normandy,’ only he works his ghostship a little differently.”

He was about to move forward when a sound reached his ears which caused him to pause.  A dog was approaching—­one of the mastiffs he had met before.  The animal growled ominously and would have attacked Adam Adams had not the detective leaped into the water and begun to swim away.  The dog halted on the edge of the bank, and then there seemed nothing for the detective to do but to swim to the other side of the river, which he did, and then disappeared into the bushes.

“I think this investigation will keep—­at least for to-night,” he reasoned.  “I may as well get back to town, get some dry clothes, and go to bed.”

His adventures had tired him and he was thoroughly exhausted by the time he reached the Beechwood Hotel.  Here he explained that he had slipped into the river and readily obtained some dry garments, after which he went to bed, sleeping soundly until sunrise.

He obtained an early and substantial breakfast and then visited a clothing establishment for another suit of clothing and a hat.  From the clothing store he stepped into a drug shop, purchasing a number of chemicals and also an atomizer.  Then he visited a barber shop and got a close hair cut.

At the post-office he received a letter, dropped by Charles Vapp the evening before.  It was short and to the point: