about nine o'clock
`` Ah ! '' Again the adventuress was silent for a little . `` What does he know ? '' `` Ask him , enquire why he murdered von Harden , then what business took him to Ninety-fifth Street twice this evening -- once about nine o'clock , again at midnight . '' `` You must be mad , monsieur . Karl would not dare ... '' `` You do n't know him -- or have forgotten he was trained in the International Bureau of Brussels , and there learned how to sell out both parties to a business that wo n't bear publicity . '' `` I wonder , '' the woman mused .