Was the old lady asleep or awake? Agnes did not know that Aunt Sarah ever walked in her sleep. But she knew that somnambulists did very strange things, and, of course, Aunt Sarah might be a sleep-walker.
Aunt Sarah Maltby proceeded to do a very strange thing now. There was a heavy brass key in the lock of the cupboard door. The old lady suddenly turned the key, locked the door, withdrew the key, and, clutching it tightly in her hand, marched back toward the front hall door.
It was just at this moment that Agnes Kenway was treated to a second surprise. She suddenly realized that there was a third person in the room!
It was because of no movement upon the part of the mysterious third person that Agnes made this exciting discovery. But she heard a quick sigh, or intake of breath, somewhere at the lower end of the room near the pantry door. She thought of Tom Jonah first of all; but then remembered that the old dog had gone out at bedtime and had not come in again.
Most exciting thoughts raced through Agnes Kenway’s brain. She had followed Aunt Sarah downstairs and into the dining room. But had Aunt Sarah followed somebody else here, at midnight?
“What under the sun is going on?” was Agnes’ muttered comment. “My goodness! I wish Ruth were here. Or Neale!”
The Corner House girl felt very much disturbed indeed. She did not believe in ghosts; but she did believe in burglars!
At that moment all thought of Barnabetta Scruggs went out of Agnes’ troubled mind. Aunt Sarah passed out of the dining room door into the front hall and closed the door carefully behind her. This left the great room in perfect darkness.
Agnes was actually trembling with excitement and fear. She had not thought to be afraid at all until she heard that mysterious sigh. The fact that she had no means of identifying the midnight marauder increased her fright.
There it was again—a short intake of breath! Somebody was surely hiding at the lower end of the room. Agnes must have come into the room so quietly that the unknown person did not apprehend her presence.