In the not-so-distant future, when biology is changing the human form and structure, Peter Bell the Third renews his friendship with Rowland Usher. In the new House of Usher that Rowland is creating in the Orinoco Delta, Usher is conducting experiments in genetics. Rowland's twin sister, Magdalen, who has committed suicide for reasons that no one understands, suddenly begins "haunting" the house. But this can be no supernatural apparition, no manifestation of the "afterlife." So what then has Magdalen become--if indeed this "ghost" is really her? A marvelous new novel in this long-running series by a master of biological extrapolation.