Carefully Barney’s fingers traversed the edges of the panel.  No hidden latch rewarded his search.  Again and again he examined the perfectly fitted joints until he was convinced either that there was no latch there or that it was hid beyond possibility of discovery.  With each succeeding minute the American’s heart and hopes sank lower and lower.  Two years had elapsed since he had seen the secret portal swing to the touch of Joseph’s fingers.  One may forget much in two years; but that he was at work upon the right panel Barney was positive.  However, it would do no harm to examine its mate which resembled it in minutest detail.

Almost indifferently Barney turned his attention to the other panel.  He ran his fingers over it, his eyes following them.  What was that?  A finger-print?  Upon the left side half way up a tiny smudge was visible.  Barney examined it more carefully.  A round, white figure of the conventional design that was burned into the tile bore the telltale smudge.

Otherwise it differed apparently in no way from the numerous other round, white figures that were repeated many times in the scheme of decoration.  Barney placed his thumb exactly over the mark that another thumb had left there and pushed.  The figure sank into the panel beneath the pressure.  Barney pushed harder, breathless with suspense.  The panel swung in at his effort.  The American could have whooped with delight.

A moment more and he stood upon the opposite side of the secret door in utter darkness, for he had quickly closed it after him.  To strike a match was but the matter of a moment.  The wavering light revealed the top of the ladder that led downward and the foot of another leading aloft.  He struck still more matches in search of the rope.  It was not there, but his quest revealed the fact that the well at this point was much larger than he had imagined—­it broadened into a small chamber.

The light of many matches finally led him to the discovery of a passageway directly behind the fireplace.  It was narrow, and after spanning the chimney descended by a few rough steps to a slightly lower level.  It led toward the opposite end of the castle.  Could it be possible that it connected directly with the apartments in the farther tower—­in the tower where the king was and the Princess Emma?  Barney could scarce hope for any such good luck, but at least it was worth investigating—­it must lead somewhere.

He followed it warily, feeling his way with hands and feet and occasionally striking a match.  It was evident that the corridor lay in the thick wall of the castle, midway between the bottoms of the windows of the second floor and the tops of those upon the first—­this would account for the slightly lower level of the passage from the floor of the second story.

Barney had traversed some distance in the darkness along the forgotten corridor when the sound of voices came to him from beyond the wall at his right.  He stopped, motionless, pressing his ear against the side wall.  As he did so he became aware of the fact that at this point the wall was of wood—­a large panel of hardwood.  Now he could hear even the words of the speaker upon the opposite side.