How does Cheryl respond to the situation when she discovers the water tank empty after crossing Hat Creek Rim in Chapter 12: "This Far"?

Cheryl is more scared than she's ever been on the trail but she checks her guide and finds out that there are alternate water sources several miles away. She opts to go to the less-recommended but closer water reservoir and, when she arrives, she sees that the water is thick. Severely dehydrated, she uses her water purifier and iodine pills to decontaminate the water.