nine o'clock
`` I do know , Mary ; I quite understand , '' Mr. Carrington assured her in his soothing voice , and there could be no doubt he was wondering just as hard as she . `` What o'clock does he generally go out ? '' he asked . `` At nine o'clock almost exactly every night , sir ! '' Mr. Carrington looked thoughtfully out of the window into the garden , and then at last looked down at the ink and paper and pen . Not a word was written on the paper yet . `` Look here , Mary , '' he said very confidentially .