Or, in this case, the sewer rats. Such is the rough English translation of La Fura dels Baus, the Barcelona-based Catalan theater company that has been invading major opera stages for a few years and now takes on Die Walküre, part two of the Ring in screenings tomorrow and Sunday as part of the Emerging Pictures opera series at the Bryn Mawr Film Institute.

This is a major, must-be-seen Ring, emanating from Valencia's fabulous new Palau de les Arts, an architectural wonder (I've been there) that resembles a huge white conquistador's helmet augmented by the rings of Saturn. Inside - finding the building's entrance is a challenge - the acoustically excellent, state-of-the-art theater attracts major artists.

The four-part, 16-hour Ring is conducted by one of its best proponents, Zubin Mehta, with a cast that mixes second-string Wagnerians with such stars as Peter Seiffert (Siegmund), Matti Salminen (Hunding), and Juha Uusitalo (Wotan).

With musical and dramatic matters in good hands (even with the less-than-heroic Brunnhilde of Jennifer Wilson), the surprise is that key people in the production and this video lose trust in the opera's power. This story of gods, warriors, and humanity experiencing ruin and redemption is characterized by Wagner at his most appealing, and though many moments are electrifying, others treat the piece like opera for the deaf.

The prelude, for example, is musical description at its best: A tense single chord that throbs over a panting bass line that suggests fleeing as a matter of life and death - underscored visually and superfluously in this production by trees flying by, literalizing an experience that's more vivid when left to the imagination.

But at least this Ring isn't some cerebral philosophical discourse; it's Spanish, with all the implied earthy exuberance. In contrast to the usual murky dark, this one loves red, with a Mars-like planet periodically arriving (and going into eclipse) on a bank of large video screens that covers the rear wall of the stage.

The giant ash tree in which the downtrodden hero Siegmund finds his sword sparkles, spews color, and revolves. Snow is also prevalent: That's usually a sign of desperation among stage directors, but in a country that doesn't often see much of the white stuff, the effect heightens the sense of ordeal around Siegmund and his sister/wife Sieglinde.

In contrast to Wagner's attenuated dramaturgy, the screen is usually in motion. The Act 2 confrontation of gods has the singers elevated above the stage in machinery resembling cherry pickers with a shifting video backdrop of outer space, existing as they do in unimaginably celestial realms. Of course, you see the cherry pickers being wheeled around, but that's apt too: With the gods' complicated personalities and ethics, they are indeed contraptions. Even the Flash Gordon-ish costumes aren't out of place: These characters are archetypes (and don't forget that the old Flash Gordon films copied Wagner).

The technology takes some getting used to: Slide projections create an overall stage environment that tends to envelop any nearby singers. This video technology makes the singers look juxtaposed against their environment, but given the netherworlds inhabited by Wagner's gods, it's all plausible.

The final act, in which the Valkyries pile up dead warriors, features a swaying wrecking ball of semi-naked, heavily tattooed corpses. In the final scene, Brunnhilde's hibernation begins with a beautiful, simple saucer surrounded by real flames. It's here - when the production and opera are at their best - that the video version goes into unfortunate overdrive.

Though the final "Wotan's Farewell" scene is one of the great things in all of opera - and comes off splendidly with Uusitalo's baritonal voice scaled down to accommodate the music's tenderness - the video changes shots every two seconds (literally). The effect is worse than just busy: The cuts dissolve in ways that unconsciously signal your brain that the scene is concluding when it's not. Wagner's music somehow plows through all of that, though a lesser composer would wilt.

Die Walküre

Music and libretto by Richard Wagner. Production by La Fura dels Baus; designed by Roland Olbeter; directed by Carlos Padrissa. Orquestra de la Comunitat Valenciana, Zubin Mehta conducting.

Cast:

Peter Seiffert (Siegmund)

Petra Maria Schnitzer (Sieglinde)

Matti Salminen (Hunding)

Juha Uusitalo (Wotan)

Jennifer Wilson (Brunnhilde)

Anna Larsson (Fricka)

Running time: Four hours with intermission, sung in German with subtitles. Show times: 6:30 p.m. tomorrow and 1 p.m. Sunday at Bryn Mawr Film Institute, 824 W. Lancaster Ave. Tickets: $22.50 for members, $25 for nonmembers. Information: 610-527-9898 or www.brynmawrfilm.org.

Tomorrow's show includes a 30-minute introduction by soprano Helen Huse Ralston.