Aunt Tabby woke up and shook Joshua.

“Aunt Tabby!  Aunt Tabby!” called Elaine.

“Yes, my dear,” answered the old nurse, now fully awake and straightening her nightcap.  “Joshua!”

Together the old couple came out into the living-room, still in their nightclothes, Joshua yawning sleepily still.

“Listen!” whispered Elaine.

There was the noise again.  This time it was more as though some one were beating a rat-tat-tat with something on a rock.  It was weird, uncanny, as all stood there, none knowing where the strange noises came from.

“It’s the haunts!” cried Aunt Tabby, trembling a bit.  “For three nights now we’ve been hearing these noises.”

Around and around the room they walked, still trying to locate the strange sounds.  Were they under the floor?  It was impossible to say.  They gave it up and stood there, looking blankly at each other.  Was it the work of human or superhuman hands?

Finally Joshua went to a table drawer and opened it.  He took out a huge, murderous-looking revolver.

“Here, Miss Elaine,” he urged, pressing it on her, “take this—­ keep it near you!”

The noises ceased at length, as strangely as they had begun.

Half an hour later, they had all gone back to bed and were asleep.  But Elaine’s sleep now was fitful, a constant procession of faces flitted before her closed eyes.

Suddenly, she woke with a start and stared into the semi-darkness.  Was that face real, or a dream face?  Was it the hideous helmeted face that had dragged her down into the sewer once?  That man was dead.  Who was this?

She gazed at the bedroom window, holding the huge revolver tightly.  There, vague in the night light, appeared a figure.  Surely that was no dream face of the oxygen helmet.  Besides, it was not the same helmet.

She sat bolt upright and fired, pointblank, at the window, shivering the glass.  A second later she had leaped from the bed, switched on the lights and was running to the sill.

Down-stairs, Aunt Tabby and Uncle Joshua had heard the shot.  Joshua was now wide awake.  He seized his old shotgun and ran out into the livingroom.  Followed by Aunt Tabby, he hurried to Elaine.

“Wh-what was it?” he asked, puffing at the exertion of running up-stairs.

“I saw—­a face—­at the window—­with some kind of thing over it!” gasped Elaine.  “It was like one I saw once before.”

Uncle Joshua did not wait to hear any more.  With the gun pointed ahead of him, ready for instant action, he ran out of the room and into the garden, beneath Elaine’s window.

He looked about for signs of an intruder.  There was not a sound.  No one was about, here.

“I don’t see any one,” he called up to Elaine and Atint Tabby in the window.

He happened to look down at the ground.  Before him was a small box.  He picked it up.