midnight
`` Now we are getting down to business . WHAT were your reasons for thinking that ? '' I hesitated . `` If you have any reason for believing that your midnight guest was Mr. Armstrong , other than his visit here the next night , you ought to tell me , Miss Innes . We can take nothing for granted . If , for instance , the intruder who dropped the bar and scratched the staircase -- you see , I know about that -- if this visitor was a woman , why should not the same woman have come back the following night , met Mr. Armstrong on the circular staircase , and in alarm shot him ? '' `` It was a man , '' I reiterated .