The meeting between brother and sister was tense, but without tears.  Halsey kissed her tenderly, and I noticed evidences of strain and anxiety in both young faces.

“Is everything—­right?” she asked.

“Right as can be,” with forced cheerfulness.

I lighted the living-room and we went in there.  Only a half-hour before I had sat with Mr. Jamieson in that very room, listening while he overtly accused both Gertrude and Halsey of at least a knowledge of the death of Arnold Armstrong.  Now Halsey was here to speak for himself:  I should learn everything that had puzzled me.

“I saw it in the paper to-night for the first time,” he was saying.  “It knocked me dumb.  When I think of this houseful of women, and a thing like that occurring!”

Gertrude’s face was still set and white.  “That isn’t all, Halsey,” she said.  “You and—­and Jack left almost at the time it happened.  The detective here thinks that you—­that we—­know something about it.”

“The devil he does!” Halsey’s eyes were fairly starting from his head.  “I beg your pardon, Aunt Ray, but—­the fellow’s a lunatic.”

“Tell me everything, won’t you, Halsey?” I begged.  “Tell me where you went that night, or rather morning, and why you went as you did.  This has been a terrible forty-eight hours for all of us.”

He stood staring at me, and I could see the horror of the situation dawning in his face.

“I can’t tell you where I went, Aunt Ray,” he said, after a moment.  “As to why, you will learn that soon enough.  But Gertrude knows that Jack and I left the house before this thing—­ this horrible murder—­occurred.”

“Mr. Jamieson does not believe me,” Gertrude said drearily.  “Halsey, if the worst comes, if they should arrest you, you must—­tell.”

“I shall tell nothing,” he said with a new sternness in his voice.  “Aunt Ray, it was necessary for Jack and me to leave that night.  I can not tell you why—­just yet.  As to where we went, if I have to depend on that as an alibi, I shall not tell.  The whole thing is an absurdity, a trumped-up charge that can not possibly be serious.”

“Has Mr. Bailey gone back to the city,” I demanded, “or to the club?”

“Neither,” defiantly; “at the present moment I do not know where he is.”

“Halsey,” I asked gravely, leaning forward, “have you the slightest suspicion who killed Arnold Armstrong?  The police think he was admitted from within, and that he was shot down from above, by someone on the circular staircase.”

“I know nothing of it,” he maintained; but I fancied I caught a sudden glance at Gertrude, a flash of something that died as it came.

As quietly, as calmly as I could, I went over the whole story, from the night Liddy and I had been alone up to the strange experience of Rosie and her pursuer.  The basket still stood on the table, a mute witness to this last mystifying occurrence.