“Dale, dear,” said Miss Cornelia with triumph in her voice.  “This is Mr. Anderson.”

The newcomer bowed politely, glancing at her casually and then looking away.  Miss Cornelia, however, was obviously in fine feather and relishing to the utmost the presence of a real detective in the house.

“This is the room I spoke of,” she said briskly.  “All the disturbances have taken place around that terrace door.”

The detective took three swift steps into the alcove, glanced about it searchingly.  He indicated the stairs.

“That is not the main staircase?”

“No, the main staircase is out there,” Miss Cornelia waved her hand in the direction of the hall.

The detective came out of the alcove and paused by the French windows.

“I think there must be a conspiracy between the Architects’ Association and the Housebreakers’ Union these days,” he said grimly.  “Look at all that glass.  All a burglar needs is a piece of putty and a diamond-cutter to break in.”

“But the curious thing is,” continued Miss Cornelia, “that whoever got into the house evidently had a key to that door.”  Again she indicated the terrace door, but Anderson did not seem to be listening to her.

“Hello—­what’s this?” he said sharply, his eye lighting on the broken glass below the shattered French window.  He picked up a piece of glass and examined it.

Dale cleared her throat.  “It was broken from the outside a few minutes ago,” she said.

“The outside?” Instantly the detective had pulled aside a blind and was staring out into the darkness.

“Yes.  And then that letter was thrown in.”  She pointed to the threatening missive on the center table.

Anderson picked it up, glanced through it, laid it down.  All his movements were quick and sure—­each executed with the minimum expense of effort.

“H’m,” he said in a calm voice that held a glint of humor.  “Curious, the anonymous letter complex!  Apparently someone considers you an undesirable tenant!”

Miss Cornelia took up the tale.

“There are some things I haven’t told you yet,” she said.  “This house belonged to the late Courtleigh Fleming.”  He glanced at her sharply.

“The Union Bank?”

“Yes.  I rented it for the summer and moved in last Monday.  We have not had a really quiet night since I came.  The very first night I saw a man with an electric flashlight making his way through the shrubbery!”

“You poor dear!” from Dale sympathetically.  “And you were here alone!”

“Well, I had Lizzie.  And,” said Miss Cornelia with enormous importance, opening the drawer of the center table, “I had my revolver.  I know so little about these things, Mr. Anderson, that if I didn’t hit a burglar, I knew I’d hit somebody or something!” and she gazed with innocent awe directly down the muzzle of her beloved weapon, then waved it with an airy gesture beneath the detective’s nose.