The Magical Eggs on Dragon's Lair

The politicians in a faraway town want to build a dam. This means Dragon's Lair would be submerged underwater. The politicians are not listening to the pleas of the residents. Something must be done to save Dragon's Lair.
Twins Evette and Adam, with their friends Jane and John band together to find a way to save Dragon's lair. Their journey takes them deep into the mountains of east Dragon's lair where they discover a new world worth saving.
What are the discoveries the children make that can save Dragon's lair?