"There it is again!" cried Frank, while Grace strained her eyes
eagerly toward the point. "What do you say to paddling over there and
having a look?"

"It's up to the girls," replied Allen, watching Betty's face eagerly.
"What they say goes."

"And they say 'go,'" smiled Betty whimsically. "Do you suppose we'd
go back without solving the mystery? Lead on, Macduff--we follow."

So Allen and Frank paddled hard toward the bend in the lake, the
other two canoes, which had fallen somewhat behind, quickening the
stroke to catch up with them, sensing that something unusual was
afoot.

As the canoes in the lead rounded the bend, those in them saw that
indeed the old mill had been renovated, but that the flame they had
seen had come, not from the old mill, but from a small bonfire
started farther in the woods.

And that was not all. What made them catch their breath and signal
for silence, was the figure of a man bent close to the flickering
fire, intent upon deciphering the writing on a long piece of paper,
that looked suspiciously like an official document.

So silent had been their approach that the man had not even changed
his position. Luckily the canoes were screened by heavy, overhanging
branches of trees, so that the occupants could observe without being
observed.