But they were gloating too soon. We came to the rock and the tree.

"Here," cried the new-found friend, "I'll get hold of the tree and then hold you."

Instantly he threw himself on his stomach, hooking his leg about the tree trunk. I crawled out over the ledge of slippery rock to the very edge and looked over. It was the only chance.

The old naturalist seized my legs in his hands. I slid down the rock, letting myself go.

Literally, his presence of mind had invented what was really a life chain, a human rope.

On came the canoe, Elaine in it as white as death, crying out and trying to stop or guide it as, nearer and nearer through the smooth-worn walls of the chasm, it whirled to the falls.

With a grip of steel, the naturalist held to the tree which swayed and bent, while also he held me, as if in a vise, head down.

On came Elaine--directly at us.

She stood up and balanced herself, a dangerous feat in a canoe at any time, but doubly so in those dark, swirling, treacherous waters.

"Steady!" I encouraged. "Grab my arms!"

As the canoe reached us, she gave a little jump and seized my forearms.

Her hands slipped, but I grasped her own arms, and we held each other.

The momentum of her body was great. For an instant I thought we were all going over. But the naturalist held his grip and slowly began to pull himself and us up the slippery rock.

A second later the canoe crashed over the falls in a cloud of spray and pounding water.

As we reached the bank above the rock, I almost lifted Elaine and set her down, trembling and gasping for breath. Before either of us knew it the queer old fellow had plunged into the bushes and was gone without another word.

"Walter," she cried, "call him back, I must tell him how much I owe him--my life!"

But he had disappeared, absolutely. We shouted after him. It was of no use.

"Well, what do you think of that?" cried Elaine. "He saved my life--then didn't wait even to be thanked."

Who was he?

We looked at each other a moment. But neither of us spoke what was in our hearts.

CHAPTER XV

THE FLASH

Alone in the doorway before his rude shack on the sh.o.r.e of the promontory sat an old fisherman, gazing out fixedly at the harbor as though deeply concerned over the weather, which, as usual, was unseasonable.

Suddenly he started and would have disappeared into his hut but for the fact that, although he could not himself be seen, he had already seen the intruder.

It was a trooper from Fort Dale. He galloped up and, as though obeying to the letter his instructions, deliberately dropped an envelope at the feet of the fisherman. Then, without a word, he galloped away again.

The fisherman picked up the envelope and opened it quickly. Inside was a photograph and a note. He read:

FORT DALE PROFESSOR ARNOLD,

J. Smith, clerk in the War Department, has disappeared.

We are not sure, but fear that he has a copy of the new Sandy Hook Defense Plans. It is believed he is headed your way. He walks with a slight limp.

Look out for him.

LIEUTENANT WOODWARD.

For a long time the fisherman appeared to study the face on the photograph until he had it indelibly implanted in his memory, as if by some system such as that of the immortal Bertillon and his clever "portrait parle," or spoken picture, for scientific identification and apprehension. It was not a pleasant face and there were features that were not easily forgotten.

Finally he turned and entered his hut. Hastily he took off his stained reefer. From a wooden chest he drew another outfit of clothes. The transformation was complete. When he issued forth from his hut again, it was no longer the aged disciple of Izaac Walton. He was now a trim chauffeur, bearded and goggled.

In the library of his bungalow, Del Mar was pacing up and down, now and then scowling to himself, as though there flashed over his mind stray recollections of how some of his most cherished plans were miscarrying.

Still, on the whole, he had nothing to complain of. For, a moment later the valet entered with a telegram for which he had evidently been waiting. Del Mar seized it eagerly and tore open the yellow envelope.

On the blank was printed in the usual way the following non-committal message:

WASHINGTON, D. C., August 12, 1915.

MR. DEL MAR,

What you request is coming. Answer to sign of the ring.--SMITH.

"Good," muttered Del Mar as he finished reading. "Strange, what a little gold will do--when you know how to dispose of it."

He smiled cynically to himself at the sentiment.

At the little railroad station, they were quite proud of the fact that at least two of the four hacks had been replaced already by taxicabs.

It was, then, with some surprise and not a little open jealousy that they saw a new taxicab drive up and take its stand by the platform.

If the chauffeur, transformed from the lonely fisherman, had expected a cordial reception, he might better have stayed before his hut, for the glances the other drivers gave him were as black and lowering as the clouds he had been looking at.

The new chauffeur got off his seat. Instead of trying to brazen it out, he walked over to the others who were standing in a group waiting for the approaching train whose whistle had already sounded.

"I'm not going to locate here permanently," he said, pulling out a roll of bills as he spoke. "Leave any fare I claim to me," he added, pa.s.sing a bill of a good denomination to each of the four jehus.

They looked at him curiously. But what business of theirs was it? The money felt good.

"All right, bo," they agreed.