the boat."

"Well, something is ticking pretty loud, and it isn't mine," Joe
said, "for I did the same as you, and left it in my cabin. But
don't you hear that noise?"

They both listened. Clearly to them, through the silence of the
night, came a steady and monotonous tick--tick-tick--

"It's the clockwork of the automatic camera," Blake whispered.

"It can't be," answered Joe. "That's too far off. Besides, it's a
different sound."

They both listened intently.

"Tick! Tick! Tick!" came to them through the dark silence.

CHAPTER XXV

MR. ALCANDO DISAPPEARS

For several seconds Blake and Joe stood there--without
moving--only listening. And that strange noise they heard kept up
its monotonous note.

"Hear it!" whispered Joe.

"Yes," answered Blake. "The brass box--the box--he had!"

"Yes," whispered Joe. All the suspicions he had had--all those he
had laughed at Blake for harboring, came back to him in a rush.
The brass-bound box contained clockwork. Was it an alarm after
all? Certainly it had given an alarm now--a most portentous alarm!

"We've got to find it!" said Blake.

"Sure," Joe assented. "It may go off any minute now. We've got to
find it. Seems to be near here."

They began looking about on the ground, as though they could see
anything in that blackness. But they were trying to trace it by
the sound of the ticks. And it is no easy matter, if you have ever
tried to locate the clock in a dark room.

"We ought to give the alarm," said Blake.

"Before it is too late," assented Joe. "Where can it be? It seems
near here, and yet we can't locate it."

"Get down on your hands and knees and crawl around," advised
Blake. In this fashion they searched for the elusive tick-tick.
They could hear it, now plainly, and now faintly, but they never
lost it altogether. And each of them recognized the peculiar
clicking sound as the same they had heard coming from the
brass-bound box Mr. Alcando had said was his new alarm clock.

"Hark!" suddenly exclaimed Blake.

Off to the left, where was planted the automatic camera, came a
faint noise. It sounded like a suppressed exclamation. Then came
an echo as if someone had fallen heavily.

An instant later the whole scene was lit up by a brilliant
flash--a flash that rivaled the sun in brightness, and made Blake
and Joe stare like owls thrust suddenly into the glare of day.

"The dynamite!" gasped Joe, unconsciously holding himself in
readiness for a