“Cudgel your brains, my good fellow! this is very important.  Did he make no allusion to his engagement to marry Miss Silvester at Craig Fernie?  Didn’t he try to pacify her by an apology of some sort?”

The question roused Arnold’s memory to make another effort.

“Yes,” he answered.  “Geoffrey said something about being true to his engagement, or keeping his promise or words to that effect.”

“You’re sure of what you say now?”

“I am certain of it.”

Sir Patrick made another note.

“Was the letter signed?” he asked, when he had done.

“Yes.”

“And dated?”

“Yes.”  Arnold’s memory made a second effort, after he had given his second affirmative answer.  “Wait a little,” he said.  “I remember something else about the letter.  It was not only dated.  The time of day at which it was written was put as well.”

“How came he to do that?”

“I suggested it.  The letter was so short I felt ashamed to deliver it as it stood.  I told him to put the time—­so as to show her that he was obliged to write in a hurry.  He put the time when the train started; and (I think) the time when the letter was written as well.”

“And you delivered that letter to Miss Silvester, with your own hand, as soon as you saw her at the inn?”

“I did.”

Sir Patrick made a third note, and pushed the paper away from him with an air of supreme satisfaction.

“I always suspected that lost letter to be an important document,” he said—­“or Bishopriggs would never have stolen it.  We must get possession of it, Arnold, at any sacrifice.  The first thing to be done (exactly as I anticipated), is to write to the Glasgow lawyer, and find Miss Silvester.”

“Wait a little!” cried a voice at the veranda.  “Don’t forget that I have come back from Baden to help you!”

Sir Patrick and Arnold both looked up.  This time Blanche had heard the last words that had passed between them.  She sat down at the table by Sir Patrick’s side, and laid her hand caressingly on his shoulder.

“You are quite right, uncle,” she said.  “I am suffering this morning from the malady of having nothing to do.  Are you going to write to Anne?  Don’t.  Let me write instead.”

Sir Patrick declined to resign the pen.

“The person who knows Miss Silvester’s address,” he said, “is a lawyer in Glasgow.  I am going to write to the lawyer.  When he sends us word where she is—­then, Blanche, will be the time to employ your good offices in winning back your friend.”

He drew the writing materials once more with in his reach, and, suspending the remainder of Arnold’s examination for the present, began his letter to Mr. Crum.

Blanche pleaded hard for an occupation of some sort.  “Can nobody give me something to do?” she asked.  “Glasgow is such a long way off, and waiting is such weary work.  Don’t sit there staring at me, Arnold!  Can’t you suggest something?”