six o'clock
It 's just this chance crack that saved 'em . If you 're rested , ride along the west wall and try for the top again . '' For the next five hours , Porter guarded the mesa front alone . It was nearing six o'clock when Jack returned , exhausted and disappointed . He had followed the great split back until the mesa top became so cut and striated with mighty fissures that progress was impossible . `` Is n't it the devil 's own luck , '' he growled to Porter as he ate , `` that we should have let him get into that one crack ! What next !