She put them together. They were pieces of the envelope of the letter which we had decided to send to Washington.

"Which way did they take him?" she asked, looking all about but discovering no trail.

She was plainly at a loss what course to pursue.

"What would Craig do?" she asked herself.

Finding no answer, she stood thinking a moment, slowly tearing the envelope to pieces. If she were to do anything at all, it must be done quickly. Suddenly an idea seemed to occur to her. She threw the pieces of paper into the air and let them blow away. It was unscientific detection, perhaps, but the wind actually took them and carried them in the direction in which the men had forced me to walk.

"That's it!" cried Elaine to herself. "I'll follow that direction."

Meanwhile, the men had hurried me off along a trail that led to the foot of a cliff. Then the trail wound up the cliff. We climbed it until we reached the top.

There in the rock was a rude stairway. I drew back. But one man drew a gun and the other preceded me down. Along the steep stone steps cut out in the face of the rock, they forced me.

Below, in a rift in the very wall of the cliff, was a cave in which already were two more of Del Mar's men, talking in low tones, in the dim light.

As we made our way down the breakneck stairway, the foremost of my captors stepped on a large flat rock. As he did so, it gave way slightly under his foot.

A light in the cave flashed up. Under the rock was a secret electric connection which operated a lamp.

"Some one coming," muttered the two men, on guard instantly.

It was a somewhat precarious footing as we descended and for the moment I was more concerned for my safety from a fall than anything else. Once my foot did slip and a shower of pebbles and small pieces of rock started down the face of the cliff.

As we pa.s.sed down, the man behind me, still keeping me covered, raised the flat stone on the top step. Carefully, he reset the connection of the alarm rock, a series of metal points that bent under the weight of a person and made a contact which signalled down in the cavern the approach of any one who did not know the secret.

As he did so, the light in the cavern went out. "It's all right," said one of the men down there, with a look of relief.

We now went down the perilous stairway until we came to the cave.

"I've got a prisoner--orders of the Chief," growled one of my captors, thrusting me in roughly.

They forced me into a corner where they tied me again, hand and foot.

Then they began debating in low, sinister tones, what was to be done with me next. Once in a while I could catch a word. Fear made my senses hypersensitive.

They were arguing whether they should make away with me now or later!

Finally the leader rose. "It's three to one," I heard him mutter. "He dies now."

He turned and took a menacing step toward me.

"Hands up!"

It was a shrill, firm voice that rang out at the mouth of the cave as a figure cut off what little light there was.

Elaine pa.s.sed along, hunting for the trail. Suddenly a shower of pebbles came falling down from a cliff above her. Some of them hit her and she looked up quickly.

There she could see me being led along by my captors. She hid in the brush and watched. During all the operations of the descent of the rock stairway and the resetting of the alarm, she continued to watch, straining her eyes to see what they were doing.

As we entered the cave, she stepped out from her concealment and looked sharply up at us, as we disappeared. Then she climbed the path up the cliff until she came to the flight of stone steps leading downward again.

Already she had seen the man behind me doing something with the stone that formed the top step. She stooped down and examined the stone.

Carefully she raised it and looked underneath before stepping on it.

There she could see the electric connection. She set the stone aside and looked again down the dangerous stairway.

It made her shudder. "I must get him," she murmured to herself. "Yes, I must. Even now it may be too late."

With a supreme effort of determination she got herself together, drew my gun which she had picked up, and started down the cliff, stepping noiselessly.

At last Elaine came to the cave. She stood just aside from the door, gun in hand, and listened, aghast.

Inside she could hear voices of four men, and they were arguing whether they should kill me or not. It was four against one woman, but she did not falter.

They had just decided to make away with me immediately and the leader had turned toward me with the threat still on his lips. It was now or never. Resolutely she took a step forward and into the cave.

"Hands up!" she demanded, firmly.

The thing was so unexpected in the security of their secret hiding-place protected by the rock alarm that, before they knew it, Elaine had them all lined up against the wall.

Keeping them carefully covered, she moved over toward me. She picked up a knife that lay near-by and started to cut the ropes which held me.

As she did so, one of the men, with an oath, leaped forward to rush her. But Elaine was not to be caught off her guard. Instantly she fired. The man staggered back, and fell.

That cooled the ardor of the other three considerably, especially now as I was free, too. While she held them up still, with their hands in the air, I went through their pockets, taking out their weapons.

Then, still keeping them covered, we backed out of the cave. Backward we made our way up the dangerous flight of steps again with guns levelled at the cave entrance, Elaine going up first.

Once a head stuck itself out of the cave entrance. I fired instantly and it jerked itself back in again just in time. That was the only trouble we had, apparently.

Cautiously and slowly we made our way toward the top of the cliff.

One look backward from his motor-boat was enough for Del Mar. He must evade that inquisitive naturalist. He turned to his man.

"Get out that apparatus," he ordered.

The man opened a locker and brought out the curious submarine rescue helmet and suit. Del Mar took them up and began to put the suit on, stooping down in the shelter of the boat so that his actions could not be seen by the naturalist in the pursuing boat.

The naturalist was all this time peering ahead keenly at Del Mar's boat, trying to make it out. He bent over and adjusted the engine to get up more speed and the boat shot ahead faster.

By this time, Del Mar had put on the submarine apparatus, all except the helmet, and was crouching low in the boat. Hastily, he rolled a piece of canvas into the semblance of a body, put his coat and hat on it and set it on the seat which he had occupied before.