Welcome to the new-wave world of Cagney's where the leather is shiny and the Marines aren't the only ones wearing crew cuts.

Cagney's is inconspicuously housed among the boutiques and book stores that dot Dupont Circle. Its decor is simple and elegant -- two massive mahogany bars, brass rails, vintage Victorian lamps and wooden ceiling fans.

By day it's a popular lunch spot for Connecticut Avenue professionals. But at night, Cagney's customers pay scant attention to the menu and mahogany as they pack the place for the funky English new-wave records the DJ spins, the six-foot video screen, the 18-foot mirror where you can watch yourself dance, the "love booths" and the nightly fashion parade.

The love booths need a bit of explanation: They're curtained-off cubicles equipped with mirror, table, two chairs, Victorian lamp with dimmer switch and a heavy red curtain to cloak . . . whatever.

Isabel ("no last name please") is hip to Cagney's because "the music is cool. The video stuff is cool, too, but sometimes it prevents you from dancing because everyone is standing around watching the screen," she explains, drinking beer from the bottle and fingering her dangling sparkler earrings.

The "video stuff" is the six-foot screen hanging from the ceiling in the lower bar. Now you can see the Thompson Twins, David Bowie or A Flock of Seagulls perform the songs that are making you move. Often, dancers fixate on the video as they watch the action on the big screen. And speaking of dancing, don't worry if you don't have a partner. It's every body for itself in today's new-wave dancing.

Fashion is important to Cagneyites. As Jody, a regular, puts it, "Sometimes it looks like the center ring at the circus. It's the Commander Salamander crowd," she says, referring to the new-wave/punk clothing store in Georgetown. Girls and guys are wearing tight leather pants and jackets and their short, severe haircuts are slicked back with Tenax, the '80s alternative to Brylcreem.

Oh, and in case you're concerned about your physical safety, owner Thomas (Tommy) Keeley doesn't allow "real punks" inside. "We cater to a more affluent clientele. You know, fashionable, trendy," he says in his English accent as he sips a glass of Perrier with a twist and waves to the crowd lined up to get in.

Keeley hails from Liverpool, which he calls "the capital of Ireland." His dark-blue conservative suit is in sharp contrast to the fluorescent colors and wild outfits his customers wear.

The folks serving the drinks at Cagney's are just as effervescent and popular as their boss. Tammy, a 23-year-old bartender and Keeley's daughter, says college kids make up the majority of customers. Cagney's also draws a large continental crowd as well as Australian, English and Israeli regulars.

Cagney's "typical English fare" lunch menu includes scotch eggs, fish and chips or roast beef with Yorkshire pudding. For dinner you can order steak and kidney pie, stuffed shrimp or Empire State strip steak and more.

Regular Billy Heneghan, 23, says he comes to Cagney's because "it's a state-of-the-art type of place. You know, it's the wave of the future. It's, like, contemporary." CAGNEY'S -- Tuesday: Gentlemen's night; Wednesday: Ladies' night; Thursday, Friday and Saturday: $2 cover; Sunday: live bands at 9. One Dupont Circle NW. 659-8820. Open for lunch 11:30 to 2:30; daily happy hour 4 to 7. Weekdays: last call is 1:30 a.m., bar closes at 2; Weekend: last call is 2:30, bar closes at 3 a.m.