shock.

"The flashlight--the automatic camera!" cried Blake. There was no
need for silence now.

The whole scene was brilliantly lighted, and remained so for many
seconds. And in the glare of the magnesium powder the moving
picture boys saw a curious sight.

Advancing toward the dam was a solitary figure, which had come to
halt when the camera went off with the flashlight. It was the
figure of a man who had evidently just arisen after a fall.

"Mr. Alcando!" gasped Joe.

"The Spaniard!" fairly shouted Blake.

Then, as the two chums looked on the brilliantly lighted scene,
knowing that the camera was faithfully taking pictures of every
move of their recent pupil, the boys saw, rushing toward Alcando,
a number of the men and soldiers who had been in hiding.

"He's surrounded--as good as caught," Blake cried. "So he's the
guilty one."

"Unless there's a mistake," spoke Joe.

"Mistake! Never!" shouted his chum. "Look--the brass box!"

The glare of the distant flashlight illuminated the ground at
their feet, and there, directly in front of them, was the ticking
box. From it trailed two wires, and, as Blake looked at them he
gave a start.

The next moment he had knelt down, and with a pair of pliers he
carried for adjusting the mechanism of his camera severed the
wires with a quick snap. The ticking in the box still went on, but
the affair was harmless now. It could not make the electrical
current to discharge the deadly dynamite.

"Boys! Boys! Where are you?" cried Captain Wiltsey.

"Here!" cried Blake. "We've stopped the infernal machine!"

"And we've got the dynamiter. He's your friend--"

The rest of the words died away as the light burned itself out.
Intense blackness succeeded.

"Come on!" cried Joe. "They've got him. We won't have to work the
hand cameras. The automatic did it!"

They stumbled on through the darkness. Lanterns were brought and
they saw Mr. Alcando a prisoner in the midst of the Canal guards.
The Spaniard looked at the boys, and smiled sadly.

"Well, it--it's all over," he said. "But it isn't as bad as it
seems."

"It's bad enough, as you'll find," said Captain Wiltsey grimly.
"Are you sure the wires are disconnected, boys?" he asked.

"Sure," replied Blake, holding out the brass box.

"Oh, so you found it," said the Spaniard. "Well, even if it had
gone off there wouldn't have been much of an explosion."

"It's easy enough to say that--now," declared the captain.

But la