In Legacy and Lore, Ellie, Luke and Blake continue their adventures on the island. Through the special powers gifted to them by the chief of the Croatoan Indians and their shauman, Powwaw, the trio encounters the sea god Poseidon who introduces them to their underwater neighbors. Poseidon gives them three dolphin to help the kids explore the vast Atlantic Ocean. Just as their wolves are land-based guardians, the dolphin protect the three from ocean predators and other dangers of the sea. Luke gets a horse, Pegasus, allowing the children to widen their adventures to places away from the lighthouse compound. With this new mode of transportation the children discover the dense woods and an abandoned mansion where they find relics of pirates from long ago.
Also in this volume, the tales of former exploits of those who honed their inventions are related here. Marconi, the SOS that could have saved the Titanic, the trials and triumphs of Billy Mitchell, and the struggle to project the first sound across the ocean.