They sat in the living room at Pellbrook, Miss Darrel and Iris being present, also Hughes and Lawyer Chapin.

Stone had examined the sitting room where Mrs. Pell had died, and, closing its door, had returned to the big living room, for further information on the whole subject of the crime and its subsequent events.

"The pin's the thing," he said, at last. "Everything hinges on that."

"Do you think so?" asked Mr. Chapin. "It seems to me the pin's a blind--a decoy--and the people hunting it are really after something else, of intrinsic value."

Fleming Stone looked at the lawyer, with a courteous impatience.

"No, Mr. Chapin, the pin is the thing they are after. It was for that pin that Mrs. Pell was murdered. That is why her dress was torn open at the throat, the villain was searching for that pin. That's why the desk was ransacked, the handbag explored, the pocket-book emptied--all in a desperate effort to find that seemingly insignificant pin! That is why the poor woman was tortured, maltreated, bruised and beaten, in final attempts to make her tell where the pin was. Failing, the wretch flung her to the floor, in a burst of murderous frenzy."

"That's why I was kidnapped, then," exclaimed Iris.

"Of course, and you may be again! Those people will stop at nothing! The letters asking for the pin, the caller who wanted it for his 'collection,' all represent the same master-mind, who is after the pin.

"But why?" wondered Hughes, "what do they want of the pin?"

"The pin means the jewels," declared Stone, briefly. "How, I can't say, exactly, for the moment, but the pin is the open sesame to the hiding-place of the gems, and only the possession of it will secure the treasure. We must get the pin--and then, all else will be clear sailing."

"But the pin is gone," lamented Iris.

"That is the worst phase of it all," Stone said, regretfully. "It is such a difficult thing to trace--not only so tiny, and easily lost, but so like thousands of others, that it can't readily be discerned even if seen."

"You think it's just an ordinary pin, then?" inquired Chapin.

"Absolutely, sir."

"Then why won't any other pin do as well?"

Stone looked at him keenly. "I can't answer that at present, Mr. Chapin; my theory regarding the pin, while doubtless the truth, is as yet uncertain. Now, another and equally great problem is that of the murderer's exit. From your story of the crime, I gather that the room was absolutely unenterable, except by breaking in the door, which Purdy and the chauffeur did?"

"That is true," agreed Iris; "the windows, as you can see, are strongly barred, and there is but the one door. Search has been made for secret entrances or concealed pa.s.sages, but there is nothing of the sort."

"No," said Stone, "this sort of a house is not apt to have such. If there were any, they would be easily discovered. And there were several people in this room, when the two men burst in the door?"

"Yes," said Iris. "I was here, and Polly, the cook, and the two men----"

"You are positive the murderer could not have slipped by you all, as the door flew open, and so made his escape?"

"That was utterly impossible. We were all grouped around the door and stayed so, until we entered the sitting room ourselves. There was n.o.body there but Aunt Ursula, herself----"

"Dead?"

"Yes, but only just dead. Polly heard her faint moans, after her loud screams, you know, before we broke in."

"And what were the words she used when she screamed out?"

"I don't know exactly, but they were cries for help, and I'm sure Polly said she called out 'Thieves!' Of course, she was unable to speak coherently."

"Now," began Stone, "to look at this one point. Her a.s.sailant had to get out or stay in, didn't he? You're sure he didn't get out, therefore he must have stayed in. A man of flesh and blood cannot go through walls, like a ghost."

"But he didn't stay in!" cried Iris. "We searched the room at once, there was n.o.body in it. You know there's almost no place to hide. We looked behind the window curtains, and all such places--and, too, we were in this room continuously, till others came, and no one could have gone through here without being seen."

"Nor could he get out of the barred windows. Then what became of him?"

"Ah, Mr. Stone," said Hughes, "that's the question that has puzzled us all. If you can solve that, we can begin to look for the murderer!"

"Meantime, we must a.s.sume him to be a spook? Is that it?" Stone smiled a little at the complacent Hughes.

"I don't say that, but I do call the manner of his exit an insoluble mystery."

"If _he_ could accomplish it, _I_ can find out how," Stone said, quietly. He had no air of bravado, but he made the statement in all sincerity.

"I believe you can!" declared Lucille. "That's why I wanted you, Mr.

Stone. I've heard of your almost unbelievable cleverness, and I knew if anybody could get to the bottom of this mystery, you could."

"I don't mind admitting that it is seemingly the most inexplicable one I ever encountered, but I shall do my best. And I want the cooperation of you all. There are many things to be told me yet; remember I've only just heard the main details, and each of you can give me light in different ways. I'll call on you for information when necessary. Also, Miss Darrel, will you extend your hospitality to my young a.s.sistant?"

"That boy?" Lucille smiled.

"Yes; Terence, his name is. He's my right-hand man and attends to a lot of detail work for me."

"He's a handful," and Lucille laughed again. "I saw him in the kitchen, wheedling round Polly, and begging for cookies."

"I'll warrant he got 'em," said Stone. "He has a way with him that is persuasive, indeed. But he won't make you any bother. Fix him up a bed in the loft, or anywhere. He's willing to rough it."

"Oh, no, he can have a decent room, of course. I'll give him one in the garage, there's a nice one next to Campbell's."

At that moment, Terence appeared at the door.

"Come in," said Stone. "I want these ladies to know you."

Awkwardly the boy entered, and blushed furiously as Stone gravely introduced him all round.

"We'll be friends, Terence," said Iris, who felt sorry for his embarra.s.sment, and who pleasantly offered her hand.

"Thank you, ma'am, and will you please call me Fibsy, it makes me feel more at home--like."

"Fibsy! What a funny name! Because you tell fibs?"

"Yes'm! How'd you guess?" The laughing eyes met hers and the boy's stubby paw touched Iris' soft hand.

But some subtle spark pa.s.sed between them, that made each feel the other a friend, and a tacit compact was sealed without a word.

"Lemme see the room?" whispered Fibsy, with a pleading look at Fleming Stone.

"Yes," and the detective rose at once, and accompanied the lad to the room of the tragedy.