“The Professor speaks very highly of him,” Quest reminded her.

“The Professor is just one of those amiable old idiots, absorbed in his mouldy old work, who would never notice anything,” Lenora persisted.  “He is just the man to be completely hoodwinked by a clever servant.”

“There is some sense in what the kid says,” Laura remarked, strolling up.  “The fact remains that Craig was one of the few men who could have got at the necklace that night, and he is also one of the few who knew about the skeleton.”

Quest sighed as he lit a cigar.

“It is a miserably obvious solution,” he said.  “To tell you the truth, girls, our friend Inspector French has had his men watching Craig ever since the night of the robbery.  What’s that?  Answer the telephone, Lenora.”

Lenora obeyed.

“It’s Inspector French,” she announced.  “He wants to speak to you.”

Quest nodded, and held out his hand for the receiver.

“Hullo, French,” he exclaimed.  “Anything fresh?”

“Nothing much!” was the answer.  “One of my men, though, who has been up Mayton Avenue way, brought in something I found rather interesting this morning.  I want you to come round and see it.”

“Go right ahead and tell me about it,” Quest invited.

“You know we’ve been shadowing Craig,” the Inspector continued.  “Not much luck up till now.  Fellow seems never to leave his master’s side.  We have had a couple of men up there, though, and one of them brought in a curious-looking object he picked up just outside the back of the Professor’s grounds.  It’s an untidy sort of neighbourhood, you know—­kind of waste ground they commenced to build over, and then the real estate man who had it in hand, went smash.”

“What is the thing?” Quest asked.

“Well, I want to see whether you agree with me,” French went on.  “If you can’t come round, I’ll come to you.”

“No necessity,” Quest replied.  “We’ve got over little difficulties of that sort.  Laura, just tack on the phototelesme,” he added, holding the receiver away for a moment.  “One moment, French.  There, that’s right,” he added, as Laura, with deft fingers, arranged what seemed to be a sensitised mirror to the instrument.  “Now, French, hold up the article just in front of the receiver.”

French’s reply was a little brusque.

“What are you getting at, Quest?” he demanded.  “You are not going to pretend that you can see from your room into this, are you?”

“If you’ll hold the object where I told you,” Quest replied, “I can see it.  I promise you that.  There, that’s right.  Hold it steady.  I’ve got the focus of it now.  Say, French, where did you say that was found?”

“Just outside the Professor’s back gates,” French grunted, “but you’re not kidding me—­”

“It’s a finger from the Professor’s skeleton you’ve got there,” Quest interrupted.

“How the blazes did you guess that?” the Inspector demanded.