The colonel tried to speak, but his voice stuck in his throat.

Slowly the veil descended.  Nick made a sign to Patsy, who had pressed up a little in advance.

He had kept an eye over his shoulder, however, to be sure of getting any orders from his chief.

There was light enough to see the signal.  Patsy sprang forward toward the specter.

The distance separating them was not more than twenty feet.  The athletic youth would have covered it in a twinkling.

But suddenly he fell to the floor with a smothered groan.

“I’m hit hard,” he cried; and, raising himself upon one knee, with his left hand pressed to his temple, he drew a revolver with the other.

“Don’t shoot!” exclaimed Nick.  “It’s Millie Stevens!”

The detective made a bound toward the figure.

The light which had played full upon it wavered, as if about to vanish.

Yet there was time.  Nick felt sure of his prize, as he sprang out from his place beside the colonel.

And the next thing Nick knew it was six o’clock of the following morning, and he was lying in a bed, looking up into Patsy’s face.

CHAPTER VIII.

Patsy’s story and the test proposed.

“Are you much hurt?” asked Patsy, anxiously.

Nick took in the whole scene before he replied.

Beside the bed were Colonel Richmond, Horace and a man whom Nick rightly judged to be a doctor.

“No,” said Nick, “I’m not much hurt, except in my feelings.  What happened, Patsy?”

“The ghost got away,” responded the young man, in a tone of disgust.

“I wouldn’t talk very much,” said Colonel Richmond.  “The doctor says that you have been subjected to a severe nervous shock, and—­”

“My grandmother’s ducks!” exclaimed Nick.  “Nervous shock!  Well, this makes me worse.  Why, man, I’ve been sand-bagged.”

The colonel shook his head.

“The power of the unseen forces,” he began; but Nick interrupted him.

“Look here, Colonel Richmond!” he said, “if you had the sensation behind your ear that I’ve got, you wouldn’t talk about mysterious powers of darkness.  I know what’s the matter with me, and what I want is a chance to get square.”

“There is no evidence of any injury,” said the physician.

“There never is in a case of this kind,” rejoined Nick.  “A sand-bag doesn’t leave any mark.  That’s why it is so popular.”

“It is impossible to convince a stubborn man,” said the colonel.  “I should think that this experience would have been enough.”

“Quite enough, thank you,” responded Nick, sitting up.  “And so, if you gentlemen who kindly put me to bed will gracefully withdraw I will get into my clothes, and prove to you that I have had enough, and that it is somebody else’s turn now.”