It was a most important discovery that Jack had made, and Rigby did not fail to see what developments it was likely to lead to. If what Masefield had said was true--and Rigby saw no reason to doubt it--here they had Anstruther directly connected with crime.

"Do you really think that our friend actually engineered that business at Lord Longworth's?" Rigby asked.

"I can come to no other conclusion," Jack replied. "You must understand that Anstruther is a kind of a specialist in crime; he has frequently been consulted by the police, and, I believe, has brought off some wonderful results. He has even written a book on the subject. Now, we know Anstruther to be an unscrupulous rascal. The police looked upon him as a brilliant aid to themselves. If a man like this chooses to play the part of a criminal Dupuin, see what marvelous opportunities he has. He knows everything about the movements of the police; he can anticipate all their schemes. It is as if Bates himself had turned burglar. Whatever Mrs. Montague might say, it is pretty certain that the embroidered scarf belongs to Anstruther. Quite inadvertently he left it at Lord Longworth's last night, where he was passing in the crowd as an invited guest."

"I know that sort of thing is done," Rigby said. "A very impudent example came under my notice the other day. The thing is much easier done than one would imagine."

"Do you mean to say," Jack asked, "that it is possible for a gentlemanly scoundrel to walk into the house of some great society lady giving a reception, and not be spotted immediately for what he is? It seems absurd!"

"Not a bit of it!" Rigby replied. "To the audacious everything is possible. Supposing a duchess is giving a reception. She has asked perhaps a thousand guests. Half-way through the evening she is so tired and worn out that she does not know or care to whom she may be speaking. Here is the chance for the gentlemanly swindler we are talking about. Of course he is perfectly dressed; he has the most exquisite manners. He lounges up to his hostess, and, after the usual greetings, makes some confidential remark about some friend of the family, which immediately stamps him as one of a certain set. All he has got to do now is to saunter along as if the whole place belonged to him, and help himself to such costly trifles as his mind inclines to."

"Did you ever know of a case in point?" Jack asked.

"My dear chap, I not only know of a case, but I was more or less party to it. It was done for a bet, and I was one of the losers. It was so easily managed that I should not in the least mind trying it myself."

"Well, it seems very odd to me," Jack murmured. "Still, if you know it has been done, there is an end of it."

"Well, it has been shown pretty conclusively," said Rigby, "that Anstruther must have been there last night."

"Quite so," Jack went on. "At any rate the scarf was left behind. I recognized it as soon as ever I saw it in Bates's hand; therefore I was absolutely sure that Anstruther had been at the reception. That is why I suggested that paragraph in the Planet. It is just the sort of silly gossip that papers publish after a sensational crime, and is calculated to hamper the police more than help them. I felt quite sure that somebody or other would bring that paragraph to Anstruther's notice, and that he would lose no time in trying to recover the scarf. I dare say there are other scarves like it in existence, but they are not so common that Anstruther could afford to take any risk. That he realized the gravity of the situation is proved by the fact that he has lost no time in calling at Lord Longworth's to recover the missing property. I think I have made my case very clear."

"Nothing could be clearer," Rigby replied. "Anstruther is at the bottom of this business. I should say he is the cleverest rascal in London at the present moment. And mark the cunning of the beast. Don't you see how easy he can prove an alibi? If he were met face to face now, and taxed with the fact that he was at Lord Longworth's last night he would politely deny it, and, if pressed, have not the slightest difficulty of demonstrating that he was elsewhere."

"But I don't quite see," Jack interrupted, "exactly how that----"

"Clear as mud," Rigby said. "Why he has only got to call his servants and Miss Helmsley to prove that he was in the study all the evening playing his violin."

"How stupid of me," Jack muttered. "The full beauty of that little scheme had been lost on me. There is a good deal we have to learn yet. But I can't stay talking to you any longer this morning, as I promised Claire that I would go and see Lady Barmouth. I have told Claire nearly everything there is to learn, and she is quite willing to be a friend of Lady Barmouth's and share her troubles. I will see you later on in the day."

Jack went off in the direction of Lord Barmouth's house. He had some little hesitation in calling so early in the day, but then the matter was imperative, and he knew that Lady Barmouth would be glad to hear Claire's decision. The lady in question was sitting in her boudoir, accompanied by two secretaries, who appeared to be tremendously busy with a long visiting list and some exquisitely-designed cards of invitation to a masked ball. But Lady Barmouth, heedless of Jack's apologies, declared that she had always time to spare for him.

"It is not I who am so busy," she said ; "in fact, this is merely mechanical work. I am giving my great party of the season, and now that I have made out the list of intended guests, the rest is merely mechanical."

So saying, Lady Barmouth led the way into an inner drawing-room, the door of which she carefully closed.

"You have some news for me," she cried eagerly. "I am quite sure you have come straight to me from Miss Helmsley."

"That is the fact," Jack said gravely. "Rather against my better judgment, I have told Claire everything. She knows now the class of man her guardian is; she knows that she will have to be terribly careful lest he should suspect. But Claire has a courage and determination which came quite as a surprise to me. I think the secret will be safe in her hands."

"Yes! yes!" Lady Barmouth cried; "but what about me?"

"I was coming to that. It seems to be a case of mutual sympathy between you. As a matter of fact it seems to me that Claire likes you as well as you like her. Anyway, she is going to see you this afternoon, when you can talk matters over without reserve. But tell me, does Lord Barmouth take any kind of interest in these festivities of yours?"

"He is goodness and kindness itself," Lady Barmouth said warmly. "He has always insisted that his misfortunes should not interfere with my personal enjoyment. At a dinner, or a reception, or an ordinary dance, my husband never sh............