About one o'clock
`` I du n no , sir ; it came like a clap o ' thunder , '' Grimes tried to lift his head , but gave over the attempt as excruciating pain followed the effort . `` What hour of the morning was it ? '' asked Ferguson . `` About one o'clock , as near as I can tell , sir . '' `` And what were you doing in the library at that hour , Grimes ? '' demanded McIntyre . `` Trying to find out what your household was up to , sir , '' was Grimes ' unexpected answer , and McIntyre started .