Six years after her perilous exploits in Eriga, Isabella embarks on her most ambitious expedition yet: a two-year trip around the world to study all manner of dragons in every place they might be found. From feathered serpents sunning themselves in the ruins of a fallen civilization to the mighty sea serpents of the tropics, these creatures are a source of both endless fascination and frequent peril. Accompanying her is not only her young son, Jake, but a chivalrous foreign archaeologist whose interests converge with Isabella's in ways both professional and personal.

Science is, of course, the primary objective of the voyage, but Isabella's life is rarely so simple. She must cope with storms, shipwrecks, intrigue, and warfare, even as she makes a discovery that offers a revolutionary new insight into the ancient history of dragons.