The Elixer

From the publishers blurb:

The village of Termiluth is the largest producer of giant blueberries, also called Varanox berries from the name of the famous wizard-botanist who created this variety of small fruits. Unfortunately this season, no flowers appeared in the fruit bushes. Strangely, the water in the pond used to water the plants turned yellow just before flowering, which may have prevented the flowers from appearing? One of the villagers was sent to bring offerings to the water fairy at the shrine in the forest, but the water fairy had disappeared. Panic begins to invade the population. Will the adventurers be able to help the village? Only them can tell...