"Well, I guess I'll be getting back," said Blake in a low voice. "No telling when things will happen now."

As he started to go away Joe remarked:

"Where are you wearing your watch? I can hear it over here."

"Watch! I haven't mine on," Blake answered. "You can't see it in the dark, so I left it on 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.