No question, it is a daring project.

The Cornish Foundation, a new charity that wants to bestow its wealth on unusual, imaginative works, has agreed to finance the completion of "Arthur of Britain, or the Magnanimous Cuckold," an opera E.T.A. Hoffmann started shortly before his death. What's more, the foundation plans to stage the opera.The risks are enormous: The Arthurian legend, the foundation directors believe, has never been effectively dramatized on stage. The foul-mouthed, slovenly young woman who will compose the opera, Hulda Schnakenburg, is possibly a genius, but then, possibly not, and she certainly is difficult to deal with. Few are entirely convinced of the artistic merit of Hoffmann's fragments. There is no libretto. And the exorbitant expense of staging the opera could yield nothing more than an embarrassing flop.

That is the premise of "The Lyre of Orpheus," by Canadian novelist Robertson Davies, the sequel to his acclaimed novel "What's Bred in the Bone" and the conclusion of the trilogy that began with "The Rebel Angels." The Cornish Foundation is the charitable legacy of Francis Cornish, the eccentric artist whose life Davies chronicled in "What's Bred in the Bone."

Does a tale about opera, 19th-century music and ancient legends make for gripping material? Well, why not? Davies is often at his best with his behind-the-scenes glimpses of the opera in production. But those who loved "What's Bred in the Bone" will be disappointed by its sequel, which offers little of the moral complexity and emotional resonance you expect from Davies.

Why? Certainly, Davies gives us many colorful characters: Arthur Cornish, the foundation chief and Francis's nephew, predictably destined to fall into the role of "magnanimous cuckold." Maria, Arthur's beautiful new wife, a gypsy's daughter frustrated by the foundation's demands on her time. Simon Darcourt, the priest-scholar stymied in his research into the life of Francis Cornish. Geraint Powell, the flamboyant Welshman who will direct the opera. Gunilla Dahl-Soot, the Scandinavian musicologist with the hollow leg and Sapphic heart. And Hoffmann himself, who watches from Limbo, where artists of unfulfilled potential are consigned.

These people are wonderful in conception, but they never come to life: You can see the author's hand contriving characters to fit preconceived roles.

Davies also gives us plenty of drama - an adultery, a birth, a stillbirth, an attempted suicide, a larceny and more than one unrequited passion. Yet it seems that nothing is happening, perhaps because the story unfolds almost entirely through the characters' erudite, quotation-splattered conversations.

It's like watching a movie in which the action takes place off screen and you learn what happens only when the characters gather to analyze it later. The garrulous folks in "The Lyre of Orpheus" are constantly holding meetings.

While he may have gone astray with this novel, Davies hasn't lost his way with words. His masterful prose remains witty, informative and brisk, and all that intellectual gabbing somehow avoids becoming ponderous.

But it doesn't soar, nor does it plumb the depths. Davies's latest novel is but a shadow of its predecessor.