“Carton,” he said confidently, “I’ll stick.”

“Good,” exclaimed the district attorney, as they fell into a conversation in low tones.

“By the way,” drawled Kennedy, “I must telephone to the office in case they need me.”

He had risen and entered the same booth.

Haddon and Carton were still talking earnestly.  It was evident that, for some reason, Haddon had lost his former halting manner.  Perhaps, I reasoned, the bomb episode had, after all, thrown a scare into him, and he felt that he needed protection against his own associates, who were quick to discover such dealings as Carton had forced him into.  I rose and lounged back to the booth and Kennedy.

“Whom did he call?” I whispered, when Craig emerged perspiring from the booth, for I knew that that was his purpose.

Craig glanced at Haddon, who now seemed absorbed in talking to Carton.  “No one,” he answered quickly.  “Central told me there had not been a call from this pay-station for half an hour.”

“No one?” I echoed almost incredulously.  “Then what did he do?  Something happened, all right.”

Kennedy was evidently engrossed in his own thoughts, for he said nothing.

“Haddon says he wants to do some scouting about,” announced Carton, when we rejoined them.  “There are several people whom he says he might suspect.  I’ve arranged to meet him this afternoon to get the first part of this story about the inside working of the vice trust, and he will let me know if anything develops then.  You will be at your office?”

“Yes, one or the other of us,” returned Craig, in a tone which Haddon could not hear.

In the meantime we took occasion to make some inquiries of our own about Haddon and Loraine Keith.  They were evidently well known in the select circle in which they travelled.  Haddon had many curious characteristics, chief of which to interest Kennedy was his speed mania.  Time and again he had been arrested for exceeding the speed limit in taxicabs and in a car of his own, often in the past with Loraine Keith, but lately alone.

It was toward the close of the afternoon that Carton called up hurriedly.  As Kennedy hung up the receiver, I read on his face that something had gone wrong.

“Haddon has disappeared,” he announced, “mysteriously and suddenly, without leaving so much as a clue.  It seems that he found in his office a package exactly like that which was sent to Carton earlier in the day.  He didn’t wait to say anything about it, but left.  Carton is bringing it over here.”

Perhaps a quarter of an hour later, Carton himself deposited the package on the laboratory table with an air of relief.  We looked eagerly.  It was addressed to Haddon at the Mayfair in the same disguised handwriting and was done up in precisely the same fashion.

“Lots of bombs are just scare bombs,” observed Craig.  “But you never can tell.”