ten o'clock
But -- he had promised the girl ! Stronger than his curiosity , stronger almost than his wish to deliver the papers , was his desire to keep that promise . It may have been foolish , quixotic ; but he resolved to continue as he had begun . `` At ten o'clock , '' he said to himself , `` if I have not found her , I will look at the papers or go to the police -- do whatever is necessary . '' He did not like to break promises or miss engagements . There was his engagement with the Wallinghams . It had absolutely gone from his mind .