In a pivotal scene this season on FX's ''The Shield,'' the pugnacious Det. Vic Mackey (Michael Chiklis) is unusually tongue-tied: A new nemesis is literally in his face, threatening to blow the lid off his corrupt control of the local drug trade. But it's not some street thug: It's fellow detective Claudette Wyms, played by the wonderfully intense CCH Pounder.
''She's the moral center,'' says Pounder, a 50-year-old stage-trained actress whose first TV job was a guest stint on ''Hill Street Blues'' in 1981. (More recently, she's appeared on ''The X-Files'' and ''The Practice.'') ''That's the reason Mackey avoids her. She's the one person who can look at him and penetrate him. He doesn't take BS from anybody -- except Claudette.''
Playing the adrenaline-charged, street-smart do-gooder is a welcome change for the demure, soft-spoken Pounder (first name CCH is short for Carol Christine Hilaria), especially since there are few decent parts for African-American women on TV today. (Memo to Anna Deavere Smith: You shouldn't have left ''The West Wing'' for the vacuous ''Presidio Med.'') ''It's potentially the best [role] I've had,'' Pounder says cautiously. The only reason she's even slightly wary is that her previous series' character, Dr. Angela Hicks of ''ER,'' languished instead of grew. ''But I'm giving the producers the opportunity to make it even better!''
Consider it done. ''She's a threat who will never go away,'' says ''Shield'' creator-exec producer Shawn Ryan, who promises more Wyms-Mackey showdowns in coming weeks. ''She's such a great adversary for someone like Vic who is accustomed to bulldogging his way through people. She's not somebody you can intimidate, and yet because she's a woman she's not someone he would physically bulldog.''
Off camera, it's Pounder who prevents Chiklis from being tongue-tied. Moments before he won the best actor Emmy last September, Pounder says she got a premonition that the ''Shield'' lead would win and told him to scribble down an acceptance speech. ''I have flashes of truth every now and again,'' admits Pounder. ''When I first got [the show], I figured this was a five-year show. Because boy, if that Vic doesn't get felled by then, then we are just a bunch of stupid people!''