ty's flashlight probed with a bright yellow beam, and Rick saw, in
the instant before the mist vanished and all movement ceased, that the
surface of the pool boiled gently and then was quiet.

The flashlight beam disclosed solid rock, broken only by the pipe from
which water trickled.

There was no ghost.

There was no place he could have gone.

[Illustration: _There was no place the Blue Ghost could have gone_]

There was no sign of human handiwork.

There was--nothing.

CHAPTER IV

The Old Mine

Rick, Scotty, and the two girls stood in silence and surveyed the scene
before them. They stood on the brow of the hill, looking down at the
picnic ground, at the trees under which they had stood and watched a
hair-raising apparition the night before.

Even in daylight the place somehow seemed eerie to Rick. The sun was
shining brightly and birds came and went without fear or interference on
their normal business of gathering food. A slight breeze ruffled the
foliage of the oak trees.

It was a fine, normal Virginia summer day, with no trace of the
supernormal or weird about it. Yet, Rick felt somewhat less than
relaxed, and he certainly felt puzzled.

Directly below them the pool created by the flow of spring water
glistened in the sunlight. Between their feet and the pool was solid
rock, with only a few weeds struggling for life in an occasional crack.

"This is going to be a tough nut to crack," Rick stated. "Look at that
rock wall. Obviously, we'd have seen anything living that tried to climb
down it, even in the darkness. If anyone had been standing up here, he'd
have been silhouetted against the sky."

"There was no one on the hill last night," Scotty said positively. "I
looked at every inch of it."

Barby listened to the exchange with an exasperated expression on her
face. "Can't you two believe the evidence of your own eyes? The Blue
Ghost appeared right under where we're standing. You can see for
yourselves that nothing could be hidden by anyone to make a ghost
appear. Besides, it was too real to be a trick."

"It was a ghost," Jan Miller said with quiet conviction. "Everyone has
always known there was a ghost here."

Scotty shook his head. "Everyone has always known there were ghosts in a
hundred places, if you want to consider all the folklore about spooks. A
few people have even claimed to have seen one. But who ever heard of a
haunt that put on nightly performances?"

"You have now,