"Pardon my bluntness," observed MacDonald, watching him through
partially closed eyes. "You are not telling the truth. You are
a busy man, with definite work, but that is no affair of mine. I
recognize in you a different calibre from that of these rich
young idlers in Howard's class. I am going to take you into my
confidence, for you understand the need for secrecy, and will
surely help in every way--noblesse oblige. This man Cronin, the
detective, was rather crude."

"He is honest and dependable," replied Shirley, loyally.

"Yes, but I wonder why professional detectives are so primitive.
They wear their calling cards and their business shingles on
their figures and faces. Surely the crooks must know them all
personally. I read detective stories, in rest moments, and every
one of the sleuths lives in some well-known apartment, or on a
prominent street. Some day we may read of one who is truly in
secret service, but not until after his death notice. But there,
I am talking to quiet my own nerves a bit,--now we will get to
cases."

The doctor dropped his cigar into the bronze tray on the table,
leaning forward with intense earnestness, as he continued.

"This, Mr. Shirley, is the third murder of the sort within a
week. Wellington Serral, the wealthy broker, came to a sudden
death in a private dining room last Monday, in the company of a
young show girl. He was a patient of mine, and I signed the
death certificate as heart failure, to save the honorable family