The lake rose from the bowels of the Earth to meet the day. The trickling tides rose and fell away within the small body of water. Long ago, the oceans froze, crumbled, and were blown aloft in clouds of dust that circled the earth, dirtying the atmosphere with briny filth. Sunlight petered through the haze, filtered to a dull grey. But still the lake remained.
The last wet place.
People huddled around it, coughing blood. All of them pressing forward for the chance to dip their toes into the shallow lake. To dip their hands and drink in the fluid that welled up from deep below the desert floor. Ponce de Leon had sought this, but never found it. It would have looked like any other lake in his time. It was only now, that the rest of the world had withered that it could be found.
The residents remained young, but even the young grow ill. That is the twist no one expected. They remained youthful, alive, unable to age, unable to wither, and unable to die. However, they were able to get sick.
They coughed blood, sweltered with the cold chills of fever, shivered despite the heat, and ached. Their throats were swollen and their voices raspy. They sneezed and dry-heaved, having nothing left to vomit. Their only respite came when sipping from the pool. But the pool was small and they were many.