noon
This was Sierra Tapalquem , at the foot of which the travelers camped that night . The passage in the morning over this sierra , was accomplished without the slightest difficulty ; after having crossed the Cordillera of the Andes , it was easy work to ascend the gentle heights of such a sierra as this . The horses scarcely slackened their speed . At noon they passed the deserted fort of Tapalquem , the first of the chain of forts which defend the southern frontiers from Indian marauders . But to the increasing surprise of Thalcave , they did not come across even the shadow of an Indian . About the middle of the day , however , three flying horsemen , well mounted and well armed came in sight , gazed at them for an instant , and then sped away with inconceivable rapidity . Glenarvan was furious .