 How did Grannie Annie save the workers?
Grannie Annie strode in the lead, her absurd long-skirted black dress looking as out of place in this desert as the trees. Grannie Annie was the original research digger-upper, and when she laid the setting of a yarn on a star of the sixth magnitude, only a transportation-velocity of less than light could prevent her from visiting her "stage" in person. As that dot continued to move across the heavens in a single direction, I called Grannie's attention to it. Five minutes later Grannie was shaking his hand vigorously and mumbling introductions. Grannie Annie walked across to it and began to study its markings. Directly behind the windscreen, backs turned to me, were Jimmy Baker, Grannie, and Xartal.
 She discovered that ultraviolet could reverse the effects on them and used it to cure them.
 She found the location they all went to and helped them navigate back.  She removed the lens from the barracks that was making them sick.  She pretended to contract the fever and fooled Antler Park.  She discovered that ultraviolet could reverse the effects on them and used it to cure them.