by deliberate art, shall we find the truth ultimately permitted to appear in some subordinate incident, or individual, studiously kept in the background—­that is the craft of telling detective stories.  But, in truth, one needs to lay hold of the problem by the throat at the outset.  Deception is too much the province of the criminal and too little the business of the investigator; and where it may be possible to creep, like a snake, into a case, unknown for what you truly are, then your opportunities and chances of success are enormously increased.  It is, however, the exception when one can start without the knowledge of anybody involved, and the Scotland Yard of the future will pursue its business under very different circumstances from the present.  The detective’s work should be made easier and not more difficult.  None should know who is working on a case.  The law’s representatives should be disguised and move among the characters surrounding the crime as something other than they really are.  They will—­”

Here Hardcastle’s reflections came to an end.  Some previous notes there were of superficial accidents in the Grey Room and a rough ground plan of it; but nothing more.  He had evidently, for the time being, broken away from his environment and was merely thinking, with a pen on paper, when he died.

CHAPTER VIl

THE FANATIC

A succession of incidents, that must have perturbed the doctor and his companion in earnest, had followed upon their departure from Chadlands, and Mary soon discovered that she was faced with a terrible problem.

For one young woman had little chance of winning her way against an old man and the religious convictions that another had impressed upon him.  Sir Walter and the priest were now at one, nor did the common sense of a fourth party to the argument convince them.  At dinner Septimus May declared his purpose.

“We are happily free of any antagonistic and material influence,” he said.  “Providence has willed that those opposed to us should be taken elsewhere, and I am now able to do my duty without more opposition.”

“Surely, father, you do not wish this?” asked Mary.  “I thought you—­”

But the elder was fretful.

“Let me eat my meal in peace,” he answered.  “I am not made of iron, and reason cuts both ways.  It was reasonable to deny Mr. May before these events.  It would be unreasonable to pretend that the death of Peter Hardcastle has not changed my opinions.  To cleave to the possibility of a physical explanation any longer is mere folly and obstinacy.  I believe him to be right.”

“This is fearful for me—­and fearful for everybody here.  Don’t you see what it would mean if anything happened to you, Mr. May?  Even supposing there is a spirit hidden in the Grey Room with power and permission to destroy us—­why, that being so, are you any safer than dear Tom was or this poor man?”