ten o'clock
When the moon rose , they started . It was slow work at first , as they had some difficulty in passing the rough country lying behind the hill . Once past it , they came upon a level plain , and rode fast for some hours . At ten o'clock they halted , and lay down under the shelter of the shrubs ; mounting again at four , and riding for another three hours . `` How far do you think we are from the river now ? By the map , I should think we can not be much more than twenty miles from it . '' `` I do n't know , my lord .