strap over one shoulder held a field-glass case.

"Where in blazes have I seen that chap before?" wondered Captain Jack
Benson, staring hard. "For I have seen him--somewhere. I'd declare
that under oath."

Figure, carnage and face all strangely haunted the submarine boy, who
crouched lower, watching.

"By the great turret gun! He's skulking for a reason!" muttered Benson.
"Is he spying on the mine-planting? I wonder? Yes! That must be his
work! Long-legs, I'll keep my eyes on you!"

The stranger hastened along for perhaps a quarter of a mile further.
Then he threw himself down on the sand, choosing a position in which he
could lie flat, his head fairly well hidden behind a low ridge of sand.

Unslinging the field-glass, the stranger brought it to his eyes, closely
watching the progress of the tug.

"Ha-ha!" muttered watchful Jack, who had followed, keeping behind
another sand ridge. "So, sir!"

The minutes passed, though Jack Benson was so absorbed in watching this
long stranger that the boy had but the vaguest notions of the flight of
time.

The tug had halted, now. A great crane at the bow swung around, and a
submarine mine hung poised in the air. Then, with a rattle of chains
not audible at the distance, the mine was slowly lowered until it