We stood gazing, aghast, a second, then ran forward. Kennedy quickly examined the safe. He bent down and from the wreck took up a package, now covered with white.

As quickly he dropped it.

"That is the package that was sent," cried Elaine.

Taking it in a table cover, he laid it on the table and opened it.

Inside was a peculiar shaped flask, open at the top, but like a vacuum bottle.

"A Dewar flask!" e.j.a.c.u.l.a.t.ed Craig.

"What is it?" asked Elaine, appealing to him.

"Liquid air!" he answered. "As it evaporated, the terrific pressure of expanding air in the safe increased until it blew out the door. That is what caused the cold sweating and the groans."

We watched him, startled.

On the other side of the portieres Michael and Clutching Hand waited.

Then, in the general confusion, Clutching Hand slowly disappeared, foiled.

"Where did this package come from?" asked Kennedy of Jennings suspiciously.

Jennings looked blank.

"Why," put in Elaine, "Michael brought it to me."

"Get Michael," ordered Kennedy.

"Yes, sir," nodded Jennings.

A moment later he returned. "I found him, going upstairs," reported Jennings, leading Michael in.

"Where did you get this package?" shot out Kennedy.

"It was left at the door, sir, by a boy, sir."

Question after question could not shake that simple, stolid sentence.

Kennedy frowned.

"You may go," he said finally, as if reserving something for Michael later.

A sudden exclamation followed from Elaine as Michael pa.s.sed down the hall again. She had moved over to the desk, during the questioning, and was leaning against it.

Inadvertently she had touched an envelope. It was addressed, "Craig Kennedy."

Craig tore it open, Elaine bending anxiously over his shoulder, frightened.

We read:

"YOU HAVE INTERFERED FOR THE LAST TIME. IT IS THE END."

Beneath it stood the fearsome sign of the Clutching Hand!

The warning of the Clutching Hand had no other effect on Kennedy than the redoubling of his precautions for safety. Nothing further happened that night, however, and the next morning found us early at the laboratory.

It was the late forenoon, when after a hurried trip down to the office, I rejoined Kennedy at his scientific workshop.

We walked down the street when a big limousine shot past. Kennedy stopped in the middle of a remark. He had recognized the car, with a sort of instinct.

At the same moment I saw a smiling face at the window of the car. It was Elaine Dodge.

The car stopped in something less than twice its length and then backed toward us.

Kennedy, hat off, was at the window in a moment. There were Aunt Josephine, and Susie Martin, also.

"Where are you boys going?" asked Elaine, with interest, then added with a gaiety that ill concealed her real anxiety, "I'm so glad to see you--to see that--er--nothing has happened from that dreadful Clutching Hand."

"Why, we were just going up to our rooms," replied Kennedy.

"Can't we drive you around?"

We climbed in and a moment later were off. The ride was only too short for Kennedy. We stepped out in front of our apartment and stood chatting for a moment.

"Some day I want to show you the laboratory," Craig was saying.

"It must be so--interesting!" exclaimed Elaine enthusiastically. "Think of all the bad men you must have caught!"

"I have quite a collection of stuff here at our rooms," remarked Craig, "almost a museum. Still," he ventured, "I can't promise that the place is in order," he laughed.

Elaine hesitated. "Would you like to see it?" she wheedled of Aunt Josephine.

Aunt Josephine nodded acquiescence, and a moment later we all entered the building.

"You--you are very careful since that last warning?" asked Elaine as we approached our door.

"More than ever--now," replied Craig. "I have made up my mind to win."

She seemed to catch at the words as though they had a hidden meaning, looking first at him and then away, not displeased.

Kennedy had started to unlock the door, when he stopped short.

"See," he said, "this is a precaution I have just installed. I almost forgot in the excitement."

He pressed a panel and disclosed the box-like apparatus.

"This is my seismograph which tells me whether I have had any visitors in my absence. If the pen traces a straight line, it is, all right; but if--h.e.l.lo--Walter, the line is wavy."