Mercedes McNab

Bringing the opposite of everything her name implies, Harmony (Mercedes McNab), the Valley-girl vamp from "Buffy the Vampire Slayer," has found a new home on The WB’s "Angel," airing Wednesdays.

She’s just "a single, undead gal trying to make it in the big city," says McNab, who previously guest-starred as Harmony in a second-season episode of "Angel," currently in its fifth year.

Harmony first appeared as the vapid best pal of high-school popularity queen Cordelia Chase (Charisma Carpenter) in "Buffy," but wound up being bitten and turned into a vampire in that show’s third-season finale, "Graduation."

Still blond and beautiful, but now undead, Harmony tried to become the latest "Big Bad" in Buffy’s hometown of Sunnydale, but failed miserably at evoking any real menace.

Harmony didn’t do much better as the main squeeze of vampire Spike (James Marsters) — in days before he had a soul and fought for the good guys — winding up verbally abused and forced to play along with his fantasies of having his way with Buffy (Sarah Michelle Gellar).

When Spike finally spilled his romantic guts to Buffy, Harmony decided she’d had enough, shot him in the back with an arrow and huffed out of Sunnydale.

She headed to Los Angeles and "Angel," where she had a brief reunion with Cordelia, who had abandoned her spoiled-girl ways in favor of becoming a champion against evil. Harmony tried to emulate Cordy, but ultimately failed and hit the road — supposedly to Mexico.

"That scene got cut out," McNab says. "It was just me running away, as usual."

Turns out, Harmony didn’t go far. In last season’s finale, Angel (David Boreanaz), the first — but not, as it happens, only — vampire with a soul, was given wealth, power and the Los Angeles office of his chief nemesis, the demonic law firm of Wolfram & Hart. Unfortunately, he also lost his son (Vincent Kartheiser), and Cordy ended up in a coma.

Coincidentally, Harmony was working in the steno pool. Angel associate Wesley (Alexis Denisof) thought a familiar face would be welcome, so he hired her as Angel’s secretary.

"Cordy is my idol, so I want to follow in her footsteps, minus the coma," McNab says.

Harmony’s also sworn off killing people. "She’s onto the pig blood now," McNab says. "She’s a good girl — trying to be."

Just when Harmony thought she had the whole new-career thing going, Spike reappeared. Having burnt to cinders while saving the world in the "Buffy" finale, he wound up the victim of a Wolfram & Hart double-cross and now is a non-corporeal entity, trapped between being undead and really, truly dead.

Harmony soon learned that Spike consummated his desire for Buffy, but she can’t quite write him off. "Good old Harmony," McNab says. "The puppy love she has for him, she has to make it OK, give it some closure. Her first instinct when she sees him is definitely excitement, which is a dead giveaway to how she feels about him."

This raises the question that if Spike ever gets a body again, will he and Harmony give it another go ? "I definitely think the door is open for the possibility," McNab says. "James and I were discussing it, and I was like, ’It must be hard for Spike, the way my character’s written, to find ways to like her, because any normal person would say, "This chick is annoying, go away."’

"And he’s like, ’Yeah, that’s what he loves about her, that she’s like that. She’ll say anything, and he thinks it’s endearing and charming and sweet, as opposed to annoying.’ So, it works."

He’s playing into that when we have our scenes together. So that, and my dialogue, leaves the door open for that possibility."

It turns out McNab and Marsters briefly opened the romantic door when she was in "Buffy." "I went on a date with James," McNab says. "We’re just buddies. It didn’t really go any further than that."

Told that Marsters has just turned 41, the 23-year-old McNab is flabbergasted. "What ? I had no idea he was that old. Oh, my gosh, I had no idea. That’s hysterical. I always thought he was in his late 20s, early 30s. At least he looks young for his age."

McNab had planned to move to New York — and did, for a while — when the stint in "Angel" came up. But, her dream was to be in "Law & Order."

"That’s my favorite show. Unfortunately, they were on hiatus the whole time I was there. I was so bummed, because I was like, ’You know how they start with that dead person on the floor ? I’ll do that.’"

Currently signed for 17 of 22 "Angel" episodes, she has no regrets. "Going to work every day is a pleasure. I know that sounds too cliche, but it’s true."

While her relationship with Spike remains in literal limbo, Harmony is trying hard to make nice with the boss. "Everyone takes her with a grain of salt. But she’s working hard, and Angel, he doesn’t want to let on that he’s OK with it yet, but I think he’s warming up to her.

"Obviously, he trusted her before, then she let him down. Now, he’s a little more guarded with her, but slowly but surely, she’s wearing him down. Eventually, he will more help her than just tolerate her."

With Cordy in a coma — and the resulting departure of Carpenter — McNab adds a welcome female presence to the show. The only other woman around on a regular basis is Amy Acker, who plays science-oriented Fred. But, McNab doesn’t anticipate any girly get-togethers for the two.

"I don’t know if Fred would have the patience for Harmony. As long as people don’t take Harmony too seriously, it’s OK. But, Fred is a pretty serious character, so I don’t know if she could put up with Harmony’s babbling."

CYBERSPATIAL ANOMALIES : "Craving Spike" at www.cravingspike.com features a biography and filmography for McNab, along with loads of "Buffy," "Angel" and Spike info.