The man must be humored in order to secure delay.

“Colonel Richmond,” said Nick, “I wish to suggest to you a final test in this matter.  It will settle all doubt and satisfy me thoroughly.

“If you can convert me to your views, I should think the achievement might be worth the trouble.”

“It would, indeed,” cried the colonel, with sparkling eyes.

Nick, with his usual tact, had hit upon exactly the right course.

“You believe, of course,” he said, “that the spirits of the dead cannot be stopped by bolts and bars.”

The colonel smiled, and nodded assent.

“The most of the jewels in dispute are, I believe, in the vaults of a safe deposit company,” Nick continued.  “Very well; my test is this:  Name some article of the collection which you are sure is there, and see whether your aunt will transfer it to Miss Stevens’ possession.

“It should be as easy for a ghost to take anything from the vaults of a safe deposit company as from that dressing-table upstairs.  Will you consent to the test?”

The colonel stood irresolute.

“Consent,” said a voice, as of a woman standing beside them.

Yet the three men were the only human beings in that room.

“The voice came from that screen!” cried Patsy, and he leaped toward the old fire-place.

He tore away the screen.  No one was there.

“It was my aunt’s voice,” said the colonel, calmly.  “I consent.”

“Consent to what?” asked Horace Richmond, entering the room at that moment.

The test was explained to him.

“Good!” he whispered to Nick.  “A fine idea.”

“Name a piece of jewelry,” said the detective to the colonel.

“Among all her wonderful collection,” replied Colonel Richmond, speaking slowly, “there was no piece of which she was more proud than the gold clasp, studded with diamonds, which you well remember, Horace.”

“I do,” responded Horace.  “There is an old tradition about it.  A remote ancestor of ours is said to have brought it from the Holy Land at the time of the third crusade.”

“An ancient family,” said Nick.  “You have a right to be proud of your ancestry.  I accept the article named as the one upon which the test shall be made, provided that you are sure that it is now in the vault.”

“Perfectly certain,” responded the colonel.  “I put it there with my own hands.  Nobody else was present, except an officer of the company and my daughter.  It is utterly impossible that the jewel can have been removed.”

“I will take that for granted,” said Nick.  “The conditions of the test are that this piece shall not be found in the vault when we visit it this afternoon, and that it shall be afterward discovered in the possession of Millie Stevens.”

“Granted,” said the colonel; and then in a clear voice, as if he wanted to be sure that there was no misunderstanding in spirit land, he announced the conditions of the test.