Nia is a young cartographer who lives in a quiet village near a misty river valley. Every morning, she draws maps of the river because she loves to show people the safe paths. The valley is often covered in fog, a phenomenon that makes the river look like a white blanket. Although the fog is beautiful, it hides the rocks and the old wooden bridge. Nia always checks her maps before she starts a new drawing.
One day, a big storm comes to the valley. The rain falls for hours, and the river grows wide and fast. When the storm stops, Nia runs to the bridge and sees that it is gone. The water washed it away, so the villagers cannot cross to the other side. "The baker needs flour from the market," says Nia's mother. "If we cannot cross, we cannot buy food." Nia looks at the river and feels worried.