“She went straight to her room, and she couldn’t have lost the ring by the way, for there was a guard ring on the outside of it, and that we found on the dressing-table.

“Of course, we hunted for the ruby ring.  We took up the carpets; we made such a search as I never saw before.  The ring was not there.

“I don’t think there’s a shadow of doubt that the ring was stolen, but I can’t form an idea of how it was done.

“The more I think about it the more confused I get.  To my mind the queerest part of it is that somebody held the door, and then let go of it and vanished in a quarter of a second.  How are we going to explain that?”

“Didn’t the thief put something against the door?”

“I thought of that, and tried to work out that theory, but it’s impossible.  Not a piece of furniture was out of place, and there wasn’t a stick or a prop of any kind in the room that could have been used for such a purpose.”

“Well, that’s strange, I must admit,” said Nick.  “I guess it will be necessary for me to go down and look the ground over.”

“That’s just what we want.”

“Come along, then.  I’m ready.”

CHAPTER II.

Nick is boldly challenged.

Nick knew the old Plummer mansion well.  There is not a house to match it in this country.

A hundred years and more ago it must have been the scene of strange adventures.  It was built, certainly, by one who did not expect a peaceful and quiet life within it.

The thick stone walls, which look so unnecessarily massive, are really double.  There are secret passages and movable panels and trap-doors enough in that house to hide a man, if a regiment of soldiers was after him.

Evidently such a place offered every chance to shrewd criminals who might have a motive for playing upon the superstitious beliefs of the present proprietor.

Anybody who couldn’t get up a respectable ghost in the old Plummer house must be a very poor fakir.

The mere fact that all the doors and windows of a room were closed did not prevent any person from going in or out at will, if he knew the secrets of the house.

Nick thought of these things as he rode down there in the cars, and he prepared himself for an interesting time, chasing bogus ghosts through secret doors and panels.

But a surprise awaited him on his arrival.  Colonel Richmond met him at the door, and, by Nick’s request, took him at once to the room from which the articles had been stolen.

It was a modern room in a new part of the house.

Nick was entirely unprepared for this.  He did not know that the colonel had built any additions to the old mansion.

Colonel Richmond spoke of this remarkable feature of the case at once.

“If this thing had happened in the old part of the house,” he said, “I shouldn’t have thought that it was anything but an ordinary robbery.