Kennedy, on his part, had had an experience, though it was no more conclusive than my own. After he had left the tobacco district, he had walked up Wall Street to the subway. In the crowd he had seen Senora de Moche, although she had not seen him. He had turned and followed her until she entered the building in which Whitney and his associates had their offices. Whether it indicated that she was still leading them a chase, or they her, was impossible to determine, but it at least showed that they were still on friendly terms with each other.
In the laboratory he could always find something to do on the case, either in perfecting his chemical tests of the various drugs we had discovered, or in trying to decipher some similarities in the rough printing of the four warnings and the anonymous letter with the known handwriting of those connected with the case, many specimens of which he bad been quietly collecting. That in itself was a tremendously minute job, entailing not only a vast amount of expert knowledge such as he had collected in his years of studying crime scientifically, but the most exact measurements and careful weighing and balancing of trifles, which to the unscientific conveyed no meanings at all. Still, he seemed to be forging ahead, though he never betrayed what direction the evidence seemed to be taking.
The package of cigarettes which he had ordered downtown was delivered about an hour after his return and seemed to be the signal for him to drop work, for the meeting with Lockwood and Whitney had been set early. He stowed the package in his pockets and then went over to a cabinet in which he kept a number of rather uncommon drugs. From it he took a little vial which he shoved into his waistcoat pocket.
"Are you ready, Walter?" he asked.
"Whenever you are," I said, laying aside my writing.
Together we made our way down to the Mendoza apartment which had been the scene of the near-tragedy the night before. Outside, he paused for several moments to make inquiries about any suspicious persons that might have been seen lurking about the neighbourhood. None of the attendants in the apartment remembered having seen any, and they were now very alert after the two events, the murder and the attempted abduction. Not a clue seemed to have been left by the villain who had been called "Doc."
"How do you feel after your thrilling experience?" greeted Craig pleasantly, as Juanita admitted us and Inez came forward.
"Oh, Mr. Kennedy," she answered, with a note of sadness in her tone. "It makes me feel so alone in the world. If it were not for 'Nita—and you, I don't know what I should do."
"Doesn't Mr. Lockwood count?" asked Kennedy observantly.
"Of course—everything," she answered hastily. "But he has to be away so much on business, and—"