chum. Instead she exclaimed:

"Mr. Blackford! It's Mr. Blackford--the man who lost the five hundred
dollar bill!"

"What!" cried Amy.

"I certainly am that same Mr. Blackford," answered the young man, "and
if these aren't the Outdoor Girls, I miss my guess!"

"That's who we are--all but one of us," spoke Betty. "Oh, it's true.
Some one has Mollie a prisoner here! We tried to open the door, but
it's locked. Will you come and help us try to batter it down?"

"I certainly will. But what are you doing here? Are you camping?"

"Camping in a haunted house? I guess not!" exclaimed Grace. "The idea!
Oh, but it's good to have--a man!"

"Thank you!" laughed Mr. Blackford, who, it will be remembered, was so
fortunate as to recover his lost money through the efforts of our
heroines, as told in the first volume of this series.

"You--you aren't afraid; are you?" asked Amy.

"Afraid of what?"

"The ghost!"

"Ghost!" and he laughed heartily.

"Well, there really have been some strange goings-on here," said Betty,
standing in the doorway with her chums. She looked out at the weather.
It was not raining much now, and the thunder and lightning had about
ceased.

"Suppose you explain," proposed Mr. Blackford. "I happened to be in this
part of the country looking after some of my business interests. I was
delayed longer at one place than I expected to be, and got caught in the
storm. When I came past this house I thought I would see if I could not
be accommodated over night, for my horse was tired and needed stabling.
Instead I----"

"You are appealed to to help lay a ghost and find a missing girl," broke
in Betty. "But, oh, the last is most important! Please come and get
Mollie out!"

"Yes, I guess that is the most important. You can tell me about it
later. But I surely was astonished to meet you girls again--glad of it,
though. Now for the prisoner. Lead the way, Miss Nelson."

Flashing her lantern, the other girls keeping at her side, and Cousin
Jane bringing up in the rear, Betty advanced to the locked door. Mr.
Blackford tried the knob, and then called:

"Stand back, whoever is in there. I'm going to burst this door open!"

Grace cried out.

"Quiet!" commanded Betty. "It is the only way."

Mr. Blackford placed his shoulder down near the lock. There was a
cracking and splintering of wood, and the door suddenly flew open with a
crash.

"Mollie! Mollie!" cried Betty, as she flashed the rays of her lamp
inside