Sir Patrick put the letter into his pocket-book, and abandoned all further attempt at interpreting the meaning of it in despair.

“Enough, and more than enough, of groping in the dark,” he said. “One point is clear to me after what has happened up stairs this morning. We must accept the position in which Miss Silvester has placed us. I shall give up all further effort to trace her from this moment.”

“Surely that will be a dreadful disappointment to Blanche, Sir Patrick?”

“I don’t deny it. We must face that result.”

“If you are sure there is nothing else to be done, I suppose we must.”

“I am not sure of anything of the sort, Master Arnold! There are two chances still left of throwing light on this matter, which are both of them independent of any thing that Miss Silvester can do to keep it in the dark.”

“Then why not try them, Sir? It seems hard to drop Miss Silvester when she is in trouble.”

“We can’t help her against her own will,” rejoined Sir Patrick. “And we can’t run the risk, after that nervous attack this morning, of subjecting Blanche to any further suspense. I have thought of my niece’s interests throughout this business; and if I now change my mind, and decline to agitate her by more experiments, ending (quite possibly) in more failures, it is because I am thinking of her interests still. I have no other motive. However numerous my weaknesses may be, ambition to distinguish myself as a detective policeman is not one of them. The case, from the police point of view, is by no means a lost case. I drop it, nevertheless, for Blanche’s sake. Instead of encouraging her thoughts to dwell on this melancholy business, we must apply the remedy suggested by our medical friend.”

“How is that to be done?” asked Arnold.

The sly twist of humor began to show itself in Sir Patrick’s face.