As it was, Harry shivered slightly, though not from fear. With the
increasing wind it was growing chilly out there for one who could not warm
himself with exercise.

"It's a long time, or it seems so," muttered the young engineer presently.
"Yet I'll wager that Tom is hustling himself and others on the very jump."

Again the call of a night bird, and once more a sound from shore seemed
to answer it.

"Real birds?" wondered Hazelton, with a start of sudden curiosity. "Or
have I been listening to human signals? If so, the signals can't cover
any good or honest purpose."

That train of thought set him to listening more acutely than before. Yet,
as no more calls reached his ears the attention of the young engineer soon
began to flag.

The monotonous lapping of the waves against the stone wall, the constant
splashing of water over the rocks and the steady blowing of the wind all
tended to make the watcher feel drowsy.

"What on earth can be keeping good old Tom?" Harry wondered, more than
once.

It would have been well, indeed, had Harry kept his eyes turned oftener
toward the shore end of the wall. In that case he might more speedily
have detected the wriggling, snake-like movement of the big negro moving
toward him.