“Do you smell it?” questioned the physician.

“Yes, but not very well.  I don’t think it will affect me much.”

“I trust not, my dear Adams.  We cannot afford to lose you.  Now, what is it all about?”

“Another case, that’s all.  I don’t feel like talking about it just yet.  I’ll give you the particulars some other time.”

“And have I helped you?”

“I think you have.”

“Of course there are other powders—­and there is chloroform—­”

“I think we have struck a clue in this.  But I must be going.”

“What, so soon!” Rudolph Calkey looked hurt.  “I was thinking you’d stay the day out.  We could chat over old times—­I’ll order an extra supper—­”

“No, not to-day.  When this case is settled, I’ll come over and we’ll make an evening of it.”  And then the detective had to fairly tear himself from the doctor and the house.  They were old friends and had worked on many a case together.

Once back in his office Adam Adams smiled grimly to himself.

“Now, Mr. Tom Ostrello, it looks as if we had you good and hard,” he murmured.  “You were seen around the place at the time of the murder by Cephas Carboy, you left the bit of paper in the library, you quarrelled at one time with Mr. Langmore and also quarrelled with your mother.  The murder was committed by means of that deadly Chinese powder, and you are one of the few persons in this country who knew of the heathenish compound.  If you are innocent I rather reckon you have a heap of explanations to make.”

There were two callers who took an hour of the detective’s time, and then he prepared to return to Sidham, to learn if possible more concerning Tom Ostrello, and if anybody besides Cephas Carboy had seen him around that vicinity on the morning of the tragedy.

“Letty, I may not be back to-night,” he remarked, as he came out into the general office.  “And it may be that I’ll not be back to-morrow.”

“All right, Uncle Adam.  What shall I tell Mr. Capes?”

“Tell him that that bond matter must wait.  He’ll have to get those numbers if he possibly can.  The other record was destroyed.”

As Adam Adams spoke he drew closer to the desk at which his assistant was sitting.  He glanced down at an envelope lying there, and started slightly.

“Where did this come from, Letty?” he questioned.  The envelope was postmarked New York and the upper left-hand corner bore the notice: 

Return in 10 days to Alexander & Company, Wholesale Druggists, 22-32 Wadley Street, Rochester, N. Y.

The girl glanced at the envelope and then at her employer and blushed deeply.

“Oh, why that—­that is a note from a friend of mine.”

“A gentleman friend, I suppose.”

“Yes, Uncle Adam.  I met him last winter, at Mrs. Dally’s reception.  He is a traveling salesman for this house,” she pointed to the notice on the envelope.  “He wants me to go to the theatre with him, and I expect to go.  Mrs. Dally says he is a very nice young man.  We—­we have been out a number of times.”  And the girl blushed again.