By Owen Gleiberman
Updated October 08, 1999 at 04:00 AM EDT

The setting is a shadowy aristocratic ball in 1749 London, but the soundtrack is disco, and the mood is drenched in decadence as James Macleane (Jonny Lee Miller), a bandit posing as a paragon of society, makes bedroom eyes at the beauty-marked, heaving-bosomed Lady Rebecca (Liv Tyler). In the background, a bisexual fop (Alan Cumming) folds his red lips like a pair of rose petals.

As long as it’s willing to be a lavishly sarcastic anti-Merchant Ivory costume drama, complete with bewigged popinjays sneering at the nasty little indulgences around them, Plunkett & Macleane is watchable in a facile, trashy way. Unfortunately, most of the movie is mired in sludge, slime, mud, blood, and studiously dank cinematography.

Macleane and his partner, the dour sharpshooter Plunkett (Robert Carlyle), carve out a career for themselves as masked ”gentlemen” highwaymen, but the movie finds precious little intrigue or adventure in their holdups and escapes. Miller and Carlyle, reunited from ”Trainspotting,” both have presence to spare, but not a lot to do. The film buries them in photogenic squalor, as if depicting the 18th century as profoundly unclean were enough to seize our imagination.