Once upon a time, there was a valley full with natural resources, where civilization thrived. Yet disaster struck, inhabitants began to move out, and one day the entire valley was lost. Now, only very limited knowledge remains and only recently was it discovered the way to the valley is no longer blocked. As part of a war in a nearby kingdom, enemies sabotaged a water reservoir and caused a flood that wrecked many villages and towns. Cut off from the front, the survivors have evacuated to the Lost Valley. Here, merchants hope to set up new businesses, adventurers hope to strike it rich and army officers hope to make a name for themselves. Even one of the princesses aims to make the valley her own, far away from the politics at home. Yet little is known of how the valley fell, and in its generations of downfall the dangers in the valley have only grown... Whether the expedition will succeed or fall, only time can tell.