The farmer considered. "Seems to me there was some mention about such a
second tunnel, back when I was a boy, but I never heard about it since.
I was born and brought up in this town, and I've never seen a sign of
one. Course that doesn't mean there never was, because it might have
fallen in."

Rick made a quick decision. "It didn't," he stated. He went on to tell
Belsely what had happened the day before, pledging him to quiet for a
few days at least to give them a chance to solve the puzzle that
remained.

The farmer was delighted. "This will give me a tale to tell from now on!
Once you say I'm free to talk, that is. Well, whaddaya know! That spring
pipe has been there since Hector was a pup, and no one ever wondered
about why it went in the hill sideways until you came along! Of course
Collins must have known--him and Hilleboe, because they were the ones
who replaced the pipe a few years back."

Rick remembered that Dr. Miller had spoken of the pipe being replaced.
If Collins and Hilleboe had put in the new pipe, they may have driven it
into the hill as Dr. Miller had said, but they had most certainly
connected it with the vertical pipe inside the tunnel.

"Likely," Belsely agreed. "One more thing. We got a daylight ghost
today. Saw him arrive by car about half an hour ago. He went up to the
cornfield with a suitcase of some kind. Thought you'd like to know."

They were delighted to know! The chance to see someone operating by
daylight was too good to miss. They said a quick farewell to Belsely and
hurried off across the field.

There was no one in sight as they crossed the picnic grounds, but when
they climbed to the top of the hill and stood on the edge of the
cornfield, they could see a man in khaki clothes bending over something
between the rows of corn plants.

"Just what the ghosts were doing," Rick exclaimed. "Let's hurry and find
out what he's up to!"

They walked swiftly down the rows of corn, making no attempt at
concealment. This was a frontal attack. The stranger saw them coming and
stood up.

Rick looked him over. The man was about forty, tanned and clean-shaven,
with horn-rimmed glasses. Not at all a ghostly type.

The boys walked right up to the man and gave him a cordial hello, which
the stranger returned.

"We couldn't help being curious," Rick said. "Do you mind if we watch?"

"Not at all." He indicated the open suitcase at his feet. It contained a
built-in instrument with a meter a