While visiting his family plantation in New Orleans, Special Agent Aloysius Pendergast inadvertently uncovers evidence that his wife Helen's death whilst on safari in Africa was no accident.

Their investigation quickly betrays just how little Pendergast knew about his wife, as they uncover her fascination with John James Audubon, a local painter whose work in chronicling the wildlife of America became very influential.

Helen was a researcher on Project Aves, an attempt to create a drug that could enhance a person's latent genius by modifying a rare strain of avian influenza.

Upon learning that no attempt to recover the bird was made so that Project Aves could have human test subjects, Helen planned to reveal the conspiracy to the world and was murdered for it.

Once in the bayou, Pendergast finds the man responsible for Helen's death: Charles J. Slade, her former employer and the director of Project Aves.