seven o'clock
He realized all too clearly that he was between the horns of a dilemma . If it chanced that Doctor Boyd 's motive for killing Captain Lloyd was to secure that despatch and thus protect Nancy , it would but establish her guilt as a rebel spy . No one would be likely to believe Boyd had committed such a murder unless he _ knew _ , and feared the despatch would incriminate her if allowed to fall into Union hands . Since seven o'clock Warren had been scouring the city in search of a clue as to Doctor Boyd 's whereabouts , but without success . He had seen several of the doctor 's patients , who could only tell him that Doctor Boyd had been unexpectedly called out of town , and before going had notified them to send for Doctor Ward if they needed medical attendance during his absence . Warren met with no better success when he made inquiries at Boyd 's house . After repeated ringing of the front bell , and knocking on the basement door , the old housekeeper finally answered the door .