Fibsy was extremely, even absurdly, sensitive to irony.  Sometimes it didn’t affect him seriously, and then, again, he would be so hurt and embarrassed by it, that it fairly made him unable to talk.

In this instance, it overcame him utterly, and his funny little freckled face turned red, and his eyes lost their eagerness and showed only chagrin.

“Come, come,” said Stone, regretting his teasing, but determined to help the boy overcome his sensitiveness to it, “brace up, Fibs; you know I meant no harm.  Forgive a chap, can’t you—­and begin all over again.  I know you have something in your noddle —­and doubtless, something jolly well worth while.”

“Well—­I—­oh, wait a minute, Mr. Stone—­I’m a fool, but I can’t help it.  When you come at me like that, I lose all faith in my notions.  For it’s only a notion—­and a crazy one at that, and —­well, sir, you wait till I’ve worked it up a little further —­and if there’s anything to it—­I’ll expound.  Now, what’s my orders for to-day?”

Fibsy had an obstinate streak in his make-up, and Fleming Stone was too wise to insist on the boy’s “expounding” just then.

Instead, he said, pleasantly:  “To-day, Fibs, I want you to make a round of the drug stores.  It’s not a hopeful job—­indeed, I can’t think it can amount to anything—­but have a try at it.  You remember, Mr. Hendricks had the earache—­”

“I do, indeed!  He had it a month ago—­and what’s more, he denied it—­at first.”

“Yes; well, use your discretion for all it’s worth—­but get a line on the doctor that prescribed for him—­it was a bad case, you know—­and find out what he got to relieve him and where he got it.”

“Yessir.  Say, Mr. Stone, is Mr. Hendricks implicated, do you think?”

“In the murder?  Why, he was in Boston at the time—­a man can’t be in two places at once, can he?”

“He cannot!  He has a perfect alibi—­hasn’t he, Mr. Stone?”

“He sure has, Fibsy.  And yet—­he was in the party that discussed the possibilities of killing people by the henbane route.”

“Yessir—­but so was Mr. Patterson—­Mis’ Desternay said so.”

“The Patterson business must be looked into.  I’ll attend to that to-day—­I’ll also see Mr. Elliott about that matter of personal loans that Mr. Embury seemed to be conducting as a side business.”

“Yes, do, please.  Mr. Stone, it would be a first-class motive, if Mr. Embury had a strangle-hold on somebody who owed him a whole lot and couldn’t pay, and—­”

“Fine motive, my boy—­but how about opportunity?  You forget those bolted doors.”

“And Mr. Patterson had borrowed money of Mr. Embury—­”

“How do you know that?”

“I heard it—­oh, well, I got it from one of the footmen of the apartment house—­”

“Footmen!  What do you mean?”

“You know there’s a lot of employees—­porters, rubbish men, doormen, hallmen, pages and Lord knows what!  I lump ’em all under the title of footmen.  Anyway, one of those persons told me—­for a consideration—­a lot about the private affairs of the tenants.  You know, Mr. Stone, those footmen pick up a lot of information—­overhearing here and there—­and from the private servants kept by the tenants.”