“Keep your candy, kid; we don’t want it,” said one of the men good-naturedly, but Sam was so interested in watching the lively little dog that, fortunately, he forgot to eat for a few minutes.

“Hello!  What ails the dog?” exclaimed Tyler, suddenly.  “How queer he acts!  I believe the stuff has made him sick already!”

All eyes were turned on the poor little creature, and it was soon plain to be seen that he was suffering terribly.

“It ought not to hurt him,” said one of the men.

“Not if it’s all right,” said Tyler, going over toward Sam.  “Let me see your candy, my boy; I believe there’s something wrong with it.”

Sam dropped the chocolate that he was just conveying to his mouth, and handed the box to the detective with great alacrity.

“There’s something in it, I’m sure,” he said, after a careful scrutiny, “and I’m willing to bet the stuff is poisoned!”

A final moan from the poor little dog fully justified him in his decision.

“The dog is dead,” said one of the clerks in a solemn voice.  “So there isn’t a shadow of doubt but what the candy is poisoned.”

CHAPTER XXVIII.

A painful situation.

To say that Sam was disappointed would be describing his feelings very mildly, but in an instant the discomfiture was forgotten in a new sensation—­he had suddenly thought of Miss Marvin’s good fortune.

Suppose she had kept the box and eaten the candy!  The thought frightened Sam out of all further idea of secrecy.

In an instant he had related how he came by the candy, and the clerks were looking at each other with questioning glances.

“’Tain’t the first box of candy she’s had sent her,” said one.  “I heard Fairbanks say that she got them often from Jim Denton.”

“Yes, she’s cut Mag Brady out for good in that direction.  Well, why shouldn’t she?  She’s new and as pretty as a picture!”

“But, surely, Jim Denton didn’t send this box,” said the detective.  “If he’s sweet on the girl he wouldn’t want to poison her.”

“Well, hardly, Tyler,” laughed another of the lunchers.

“Perhaps he intended it for Mag,” suggested another.  “If he’s tired of the girl he may be trying to fix her.”

“Pshaw!  He doesn’t have to resort to such measures as that!  What could a poor girl do to injure Jim Denton?  No, Tyler, you’ll have to look somewhere else for your poisoner, I reckon,” said one of the oldest men in the whole establishment.

“Who gave you the box in the first place?” asked the detective of Sam.  “I mean, who told you to give it to Miss Marvin?”

Sam spoke up promptly, for he had nothing to hide.

“A kid gave it to me at the door—­a messenger boy—­who said he was in a tearing hurry.”

“Did you sign for it?” asked the detective, looking sharply at the boy.