“Righto!  And, say, a month or so ago, he bought some hyoscine—­”

“Oh, no, excuse me, he did not!  That’s not sold hit or miss.  But maybe you mean hyoscyamine.  That’s another thing.”

“Why, maybe I do.  Look up the sale, can’t you, and make sure.”

“Why should I?”

Fibsy explained that in the interests of a police investigation it might be better to acquiesce than to question why, and the young man proved obliging.

So Terence McGuire learned that Alvord Hendricks bought some hyoscyamine, on a doctor’s prescription, about a month ago—­the same to be used to relieve a serious case of earache.

But there was no record of his having bought hyoscyarnus, which was the deadly henbane used in the medicine dropper-nor was there any other record of hyoscyamine against him.

Satisfied that he had learned all he could, Fibsy continued his round of drug-store visits, in an ever-widening circle, but got no information on any henbane sales whatever.

“Nothin’ doin’,” he told himself.  “Whoever squirted that henbane from that squirter into that ear—­brought said henbane from a distance, which, to my mind, indicates a far-seeing and intelligent reasoning power.”

His present duty done, he started forth on his own tour of investigation.  He went to a small boarding house, in an inconspicuous street, the address of which had been given him by Mr. Barton, and asked for Mr. Hanlon.

“He ain’t home,” declared the frowning landlady who opened the door.

“I know it,” returned Fibsy, nonchalantly, “but I gotta go up to his room a minute.  He sent me.”

“How do I know that?”

“That’s so, how do you?” Fibsy’s grin was sociable.  “Well, look here, I guess this’ll fix it.  I’m errand boy to—­you know who—­” he winked mysteriously, “to the man he takes his acrobat lessons off of.”

“Oh,” the woman looked frightened.  “Hush up—­it’s all right.  Only don’t mention no names.  Go on upstairs—­third floor front.”

“Yep,” and Fibsy went quietly up the stairs.

Hanlon’s room was not locked, but a big wardrobe inside was—­and nothing else was of interest to the visitor.  He picked at the lock with his knife, but to no avail.

As he stood looking wistfully at the wardrobe door, a cheerful voice sounded behind him: 

“I’ll open it for you—­what do you want out of it?”

Fibsy looked up quickly, to see Hanlon himself, smiling at him.  Quick to take a cue, the boy didn’t show any embarrassment, but putting out his hand said, “How do you do, Mr. Hanlon?”

“Fine.  How’s yourself?  And why the sneak visit, my boy?”

Fibsy looked his questioner square in the eye, and then said, “Oh, well, I s’pose I may as well speak right out.”

“You sure may.  Either tell the truth, or put up such a convincing lie that I’ll think it’s the truth.  Go ahead.”