“I know it.  That’s what I came to see you about.”

“So you did.  I’d quite forgotten—­”

“You ought to learn to concentrate, Mr. Carroll.  It’s really ridiculously easy after you’ve studied it a little bit.  Now if I had been you, and you had been I—­me—­I never would have forgotten what you came to see me about.  Of course, I know you didn’t forget, really; but the chances are that you were interested talking, and absolutely failed to remember that poor boy.”

“What poor boy?”

“Roland Warren.”

Carroll with difficulty concealed a smile.

“I see!  And now that I’ve remembered him again, suppose you tell me what you know about him and the case?”

“It’s principally about what I read in the papers this morning.  Really, Mr. Carroll, there ought to be a law against newspapers printing such ridiculous things!”

“As what, for instance?”

“That thing they had in there this morning.  Why, the way they mentioned Hazel Gresham, you’d have thought that they thought she was the woman who killed Roland—­the woman in the taxicab.”

Carroll’s eyes narrowed slightly.  The faint smile still played about his lips.

“You don’t think she was?”

“Oh, Mr. Carroll!  Please, please, don’t be so irresistibly absurd!  Why in the world should Hazel kill the man she was engaged to?”

“I don’t know.”

“And besides, what does she know about killing some one?  That is the most bizarre idea I have ever heard in all my life.  Besides, she couldn’t have killed him, anyway.”

“Why not?”

“Even if she’d wanted to, she couldn’t; and I’m sure she didn’t want to.  Not that I think Roland Warren was the finest man in the world, or anything like that.  Of course, I do believe he was interested in me, and that made me know him pretty well; but still he was an awfully nice boy, and I’m sure Hazel was very much in love with him.  So even if she could have killed him, she wouldn’t, would she?”

“I hope not; but you said she couldn’t.  What did you mean by that?”

“I mean that nobody can be in two places at one time.  Although I did read a funny article in the Sunday magazine section of one of the big newspapers, last year, which said that—­”

“If Miss Gresham had been with Mr. Warren last night at midnight—­she would have been in two places at one time!”

“Why, yes—­and that’s not possible; so, of course, she—­”

“What makes you think that, Miss Rogers!”

“Think what?”

“That Miss Gresham was not with Mr. Warren at midnight last night?”

“Why,” answered Evelyn Rogers simply, “I know she wasn’t—­that’s all.”

“You know?”

“Yes, indeed—­beyond the what-you-call-’em of a doubt.”

“How do you know that?”

“It’s very simple,” she explained casually.  “She was with me all night.”