midnight
`` There it goes , '' Jack indicated , as the figure almost disappeared in the thick hedge . `` I thought at first the boys might be up to some prank , but that ` ghost ' walks too firmly to be a spirit . '' `` Queer for a girl to be out at this hour , '' reflected Cora . `` I wonder who it can be , and what does she want , prowling about after midnight ? '' `` Want me to investigate ? '' `` What ; run after it ? '' `` Or -- whistle , '' he said jestingly .