“This tank must be kept full of water.”

He thrust his hand gingerly into it, bringing it out quickly.  The tank was nearly full of water and he brought his hand out wet.  It was also hot.  But he did not seem to mind that, for he shook his head with a smile of satisfaction.

Next, from his capacious bag he took two metal poles, or electrodes, and fastened them carefully to the ends of the wires, placing them at opposite ends of the tank in the water.

For several moments he watched.  The water inside the tank seemed the same as before, only on each electrode there appeared bubbles, on one bubbles of oxygen, on the other of hydrogen.  The water was decomposing under the current by electrolysis.

Another moment he surveyed his work to see that he had left no loose ends.  Then he picked up his bag and moved toward the cellar steps.  As he did so, he removed the muzzle from his nose and quietly let himself out of the house.

. . . . . . . .

The next morning, Rusty, who had been Elaine’s constant companion since the trouble had begun, awakened his mistress by licking her hand as it hung limply over the side of her bed.

She awakened with a start and put her hand to her head.  She felt ill.

“Poor old fellow,” she murmured, half dazedly, for the moment endowing her pet with her own feelings, as she patted his faithful shaggy head.

Rusty moved away again, wagging his tail listlessly.  The collie, too, felt ill.  Elaine watched him as he walked, dejected, across the room and then lay down.

“Why, Miss Elaine—­what ees ze mattair?  You are so pale!” exclaimed the maid, Marie, as she entered the room a moment later with the morning’s mail on a salver.

“I don’t feel well, Marie,” she replied, trying with her slender white hand to brush the cobwebs from her brain.  “I—­I wish you’d tell Aunt Josephine to telephone Dr. Hayward.”

“Yes, mademoiselle,” answered Marie, deftly and sympathetically straightening out the pillows.

Languidly Elaine took the letters one by one off the salver.  She looked at them, but seemed not to have energy enough to open them.

Finally she selected one and slowly tore it open.  It had no superscription, but it at once arrested her attention and transfixed her with terror.

It read: 

“You are sick this morning.  Tomorrow you will be worse.  The next day you will die unless you discharge Craig Kennedy.”

It was signed by the mystic trademark of the fearsome Clutching Hand!

Elaine drew back into the pillows, horror stricken.

Quickly she called to Marie.  “Go—­get Aunt Josephine—­right away!”

As Marie almost flew down the hall, Elaine still holding the letter convulsively, pulled herself together and got up, trembling.  She almost seized the telephone as she called Kennedy’s number.