For the time, Kennedy dropped his investigations in the laboratory and we went down to O'Hanlon's office, where a thick batch of warrants, just signed, had been received.
Quickly O'Hanlon disposed his forces so that in all parts of the town they might swoop down at once and gather in the medical harpies. Dr. Loeb's stood first on the list of those which O'Hanlon decided to handle himself.
"By the way," mentioned O'Hanlon as we hurried uptown to be ready in time, "I had a letter from Darius Moreton this morning threatening me with all kinds of trouble unless we let up on Dr. Loeb. It's pretty hard to keep a big investigation like this secret, but I think we've planned a little surprise for this morning."
With the post-office inspector we climbed into a patrol wagon with a detail of police who were to make a general round-up of the places on Forty-second Street.
As the wagon backed up to the curb in front of the building in which Loeb's office was, the policemen hopped out and hurried into the building before a crowd could collect. Unceremoniously they rushed through the outer office, headed by O'Hanlon.
Quickly though the raid was executed, it could not be done without some warning commotion. As we entered the front door of the office, we could just catch a glimpse of a man retreating through a back door. There was something familiar about his back, and Kennedy and I started after him. But we were too late. He had fled without even waiting for his hat, which lay on Miss Golder's desk, and had disappeared down a back stairway which had been left unguarded.
"Confound it," muttered O'Hanlon, as we returned, "Loeb hasn't been here today. Who was that?"
"I don't know," replied Craig, picking up the hat, underneath which lay a package.
He opened the package. Inside were half a dozen Berkefeld filters, those peculiar porcelain cones such as we had found out at Norwood.
Quickly Craig ran his eye over the mass of papers on Miss Golder's desk. He picked up an appointment book and turned the pages rapidly. There were several entries that seemed to interest him. I bent over. Among other names entered during the past few days I made out both "Moreton" and "Dr. Goode." I recalled the letter which O'Hanlon had received from Moreton. Had he or someone else got wind of the raids and tipped off Dr. Loeb?