The Cornish Foundation is thriving under the directorship of Arthur Cornish when Arthur and his beguiling wife, Maria Theotoky, decide to undertake a project worthy of Francis Cornish, whose vast fortune endows the Foundation. The remarkably unattractive, extraordinarily talented music student Hulda Schnakenberg is commissioned to complete E. T. A. Hoffmann's unfinished opera Arthur of Britain, or The Magnanimous Cuckold; and the scholarly priest Simon Darcourt finds himself charged with writing the libretto.

Complications both practical and emotional arise: the gypsy in Maria's blood rises with a vengeance. Darcourt stoops to petty crime; and various others indulge in perjury, blackmail, and other unsavory pursuits. Hoffmann's dictum, "the lyre of Orpheus opens the door to the underworld," seems to be all too true - especially when the long-hidden secrets of Francis Cornish himself are finally revealed.