with all their vague and weird imaginings.

But in this expectation they were most completely disappointed. Nothing at
all unusual occurred and although they enjoyed their swim in the warm back
eddy of the pool, they came away disgruntled and with a curious feeling
that they had been cheated out of something.

"I only wish the boys would come," sighed Amy, as they turned in once more
at the lodge.

After that the "Thing" became almost like an obsession with them. They
must find out definitely what it was that was spoiling all their fun. They
began to haunt the river, especially at the foot of the falls, in the hope
of seeing something, anything that would put an end to their curiosity and
uneasiness.

For a long time they had not got up courage enough to visit the place at
night, but at last they became curious enough to brave even that.

"We have simply got to find out something," Mollie whispered to Betty as
on this particular night they stood on the porch and waited for Mrs.
Irving to join them. "We can't go on this way any longer, Betty. Why, I am
getting so nervous I jump if you look at me."

"I know," said Betty soberly. "It really is getting on our nerves too
much. Amy and Grace are feeling it even worse than we are."

"Yes," agreed Mollie grumpily. "Last night was the third night in
succession that Amy got us all out of bed to listen to some fool noise
outside. I'm just about sick of it."