He lit a cigar as they struggled back along the path.  Presently they reached the untidy-looking avenue, and a few minutes later arrived at the house.  Quest looked around him in something like bewilderment.

“Say, fancy keeping a big place like this, all overgrown and like a wilderness!” he exclaimed.  “If the Professor can’t afford a few gardeners, why doesn’t he take a comfortable flat down town.”

“I think it’s a horrible place,” Lenora agreed.  “I hope I never come here again.”

“Pretty well obsessed, these scientific men get,” Quest muttered.  “I suppose this is the front door.”

They passed under the portico and knocked.  There was no reply.  Quest searched in vain for a bell.  They walked round the piazza.  There were no signs of any human life.  The windows were curtainless and displayed vistas of rooms practically devoid of furniture.  They came back to the front door.  Quest tried the handle and found it open.  They passed into the hall.

“Hospitable sort of place, any way,” he remarked.  “We’ll go in and wait, Lenora.”

They found their way to the study, which seemed to be the only habitable room.  Lenora glanced around at its strange contents with an expression almost of awe.

“Fancy a man living in a muddle like this!” she exclaimed.  “Not a picture, scarcely a carpet, uncomfortable chairs—­nothing but bones and skeletons and mummies and dried-up animals.  A man with tastes like this, Mr. Quest, must have a very different outlook upon life from ordinary human beings.”

Quest nodded.

“He generally has,” he admitted.  “Here comes our host, any way.”

A small motor-car passed the window, driven by Craig.  The Professor descended.  A moment or two later he entered the room.  He gazed from Quest to Lenora at first in blank surprise.  Then he held out his hands.

“You have good news for me, my friends!” he exclaimed.  “I am sure of it.  How unfortunate that I was not at home to receive you!  Tell me—­don’t keep me in suspense, if you please—­you have discovered my skeleton?”

“We have found the skeleton,” Quest announced.

For a single moment the new-comer stood as though turned to stone.  There was a silence which was not without its curious dramatic significance.  Then a light broke across the Professor’s face.  He gave a great gulp of relief.

“My skeleton!” he murmured.  “Mr. Quest, I knew it.  You are the greatest man alive.  Now tell me quickly—­I want to know everything, but this first of all.—­Where did you find the skeleton?  Who was the thief?”

“We found the skeleton, Professor,” Quest replied, “within a hundred yards of this house.”

The Professor’s mouth was wide open.  He looked like a bewildered child.  It was several seconds before he spoke.

“Within a hundred yards of this house?  Then it wasn’t stolen by one of my rivals?”

“I should say not,” Quest admitted.