The detective was in doubt whether to enter the house in his own character.  Finally he decided not to do so.

He disguised himself in the character of John Gilder, the coachman, who was not present in the parlor.

It seemed best to gain access to the room from an entrance toward the old part of the house instead of from the main hall.

So Nick passed around the corner of the house.  As he did so he was aware of a dark figure crouching in the shadow.

He instantly grappled with it, and the figure was not less prompt in grappling with him.

The struggle was very brief.  It ended with Nick on top, and no harm done.

The detective instantly leaped to his feet again.

“Patsy!” he exclaimed.  “What brings you here?”

CHAPTER VII.

A really competent ghost.

Patsy told his story in a few words.

He had watched the Stevens house all day without discovering anything.

As evening descended, however, his patience had been rewarded.

“She came out,” said Patsy, “and quietly scooted off across the fields.”

“Millie Stevens?”

“Yes.”

“What did she do?”

“She made for that big oak tree which stands in the middle of the field on the right of the road as you go from the station.

“I had to trail carefully, for it was not very dark and there was no cover.  So I couldn’t get very near her.

“Under that tree a man was waiting.  He had a saddle-horse with him.  The man and the girl exchanged a few words.

“Of course, I couldn’t hear what they said.  Neither could I get a line on the man.

“I resolved to get nearer, though it was taking big risks.  It couldn’t be done.  They saw me.

“In a flash the man leaped into his saddle and pulled the girl up in front of him in regular old-fashioned style.

“They were off in no time.  It was a fine horse they rode.

“I wasn’t in it at any stage of the game.  I ran myself out at the end of about a mile.

“They had disappeared in the darkness, but they were taking the road toward this place, and on a venture I came over.  I hoped to connect with you, and get instructions.”

“That was right.  Come with me.”

“What’s up?”

“A ghost hunt, unless I’m very much mistaken.  I guess we can join it without any trouble.”

They made their way into the old portion of the house.

In the hall from which the broad stone stairs led up to the second floor they paused a moment to listen.

Steps were approaching.  Before they could get into a place of concealment a door opened, and Colonel Richmond entered.

He carried a small lamp in his hand.  Horace followed him.

“Gilder!” cried the colonel, seeing Nick disguised as the coachman.  “Why were you not present in the parlor?”