Cassie moves from the city into the home of her Nana. Her parents are off on a venture to the South American Rain Forests. They often send her odd gifts and notes about how important it is to follow her heart and to protect the plants and animals around her. Cassie explores the meadow. She makes friends with the animals and learns the names of the plants. She is haunted by a face she finds looking up at her from the pond. Although it looks just like her it is not her reflection! The girl under the surface of the water eventually leads her to a beautiful metal gate hidden under the waterfall that cascades into the pond. The gate is locked with a padlock in the shape of a flower. The padlock looks very much like the key her parents sent to her form South America to use to "guard the secrets of the meadow". She uses the delicate key to unlock the decorative padlock opening the gate and finds her twin on the other side of the gate. Follow the adventures of Cassie and Lilly as they search for a way to protect Lilly's home by informing neighbors that polluting the environment actually harms other people animals and plants