night."
"It's quite true," said Miss Carrol quietly. "I lost myself in the fog."
"But why did you leave the house?"
"I shall explain that to Inspector Harkness. Dear Ma," Patricia patted the disturbed old woman's shoulder kindly, "don't cry so. I assure you I have nothing to do with the death of poor Mrs. Pentreddle."
"I never thought for one minute you had, my dear," said the poor landlady. "All the same, Martha is as dead as a door-nail. She is now with her late husband I expect, though it can't be a very pleasant place where such a rascal has gone to. Not that I want to say anything bad against them that are gone, for we may be the same to-morrow," and so poor Mrs. Sellars, quite incoherent with grief and bewilderment, maundered on aimlessly.
Patricia was invited to enter the drawing-room by a jovial-looking man, whose would-be military air did not suit his looks. He was stout, red-faced, grey-haired and bluff in his manner, resembling the typical John Bull more than anything else. He tried to be stiff, but failed in his buckram civilities when he forgot that he was Inspector Harkness and remembered that he was primarily a human being. Miss Carrol was so pretty and graceful in spite of her white face and drooping air, the result of fatigue, that the officer beamed on her approvingly. But having placed a chair for her, and one for Mrs. Sellars, who was to be present at the interview, he became aware that he had his duty to perform, and looked as stern as he possibly could.
"Now, young lady," he said, arranging some papers, and getting ready to take notes, "what do you know of this matter?"
"Nothing," said Patricia, coolly and decisively. She was now quite her own clever, ready-witted self, as the difficulties of her position had acted upon her like a tonic. In spite of Inspector Harkness's suave demeanour, she was fully aware that he would not hesitate to arrest her, if he believed she was in any way inculpated. Her curt answer rather annoyed him.
"Nothing," he repeated sharply. "That is rather a strange denial to make, in the face of the fact that you were the last person who saw this unfortunate lady alive. Do you deny that, Miss Carrol?"
"No. Why should I? I was with Mrs. Pentreddle from the time Mrs. Sellars left with the others for the Curtain Theatre----"
"Half-past six, as we thought the house would be full," interpolated Ma sadly.
--"until nearly half-past eight o'clock," finished Patricia calmly.
"And after that?" asked Harkness, noting down this fact and acknowledgment.
"I was wandering about Hyde Park, lost in the fogs until half-past eleven."
"What took you to Hyde Park on this night?"
"Mrs. Pentreddle asked me to go on an errand for her."
"What was the errand?"
"What indeed?" said Mrs. Sellars curiously. "Martha, poor dear, was always of a very secretive disposition, and never told me anything. But, as I am her own sister, she ought to have told me what she wanted."
Patricia took no notice of this remark, but addressed herself to Inspector Harkness. She wished to get the interview over, so that she could retire to bed, for she felt extremely tired, and only her will-power enabled her to sustain the examination. "Mrs. Pentreddle," she explained, and the officer took down her words, "had an appointment to-night with a man near the Serpentine Bridge on this side. Owing to her sprained ankle she could not go herself, so she promised me five pounds if I would go in place of her. At first I objected, since the conditions under which I was to meet this man were so strange; but when Mrs. Pentreddle declared that, failing me, she would ring up a messenger-boy on the telephone, I thought that there could be nothing wrong, and accepted the commission."
"For the sake of the five pounds," hinted the inspector.
Patricia threw back her head proudly. "I am not rich, and five pounds mean much to me," she said simply, but with a nervous flush. "Yes, I went for the sake of the five pounds. Though, of course," she added quietly, "I was quite willing to oblige Mrs. Pentreddle in every way. I refused the money at first, but when she insisted upon paying me, I was only too delighted to accept. Do you blame me?"
"Well, no," acknowledged the officer, after a pause. "But did you not think that five pounds was a rather large sum to pay for a simple errand?"
"And Martha was so close-fisted as a rule," put in Mr. Sellars.
"The errand was not a simple one," said Patricia quickly. "There was a very great deal of mystery about it," and she repeated the instructions which the dead woman had given her. These both impressed the inspector and startled Mrs. Sellars.
"One would think that Martha was a conspirator," she exclaimed.
"Perhaps she was and perhaps she was not," replied Miss Carrol wearily. "I have been puzzling over the question ever since the box was stolen."
"Stolen!" Harkness rose suddenly to his feet and looked at the girl's pale face with an imperious glance. "What do you mean?"
"What I say," answered Patricia, whose nerves were giving way. "A man came and snatched the jewel from my hand while I looked at it."
"The jewel!" cried Mrs. Sellars alertly. "What jewel?"
"The one which was in the deal box."
"The box which this unknown man thrust into your hand?" asked Harkness.
"Of course. I should not have opened the box, but I did so, because----" Patricia hesitated. It seemed useless to tell these two very matter-of-fact people about the weird sensations which she had felt while holding the jewel, as they would neither understand nor believe. Swiftly changing her mind, she ended her sentence differently--"because the whole circumstances were so strange that I wished to know what was in the box."
"You were afraid that Mrs. Pentreddle had sent you on a nefarious errand?"
"Yes, I was, and with good reason," said Patricia, and Harkness nodded approvingly.
Mrs. Sellars disagreed. "Why, Martha was a most religious woman, and so good as to be almost unpleasant. She would never have sent you on an errand which had to do with anything wrong, my dear."
"You can judge for yourself," said Miss Carrol, quietly. "I am telling you all that has taken place."
Harkness pondered. "You say that you left this house at half-past eight, and wandered in Hyde Park until half-past eleven. How can you prove this?"
"Very easily, Mr. Inspector. I met a policeman in Crook Street when I left the house and asked him the time. He told me that it was half-past eight. At half-past eleven I spoke to another policeman near the Achilles statue, saying I had lost myself in the fog. I asked him the time also, and told him to whistle me up a cab. He said it was half-past eleven and got me the cab. Mrs. Sellars told me in my bedroom that you had questioned the cabman, sir, so he must substantiate my story."
Harkness nodded. "Yes. He told me that a policeman had put you in the cab at Hyde Park Corner about the time you mentioned. I see that you can account for leaving the house and returning to it. But what were you doing in the meantime?"
"I have told you," said Patricia, annoyed at having her word doubted.
"Yes,
