If you haven't seen Ally Sheedy since her "Breakfast Club" and "St. Elmo's Fire" days, you've missed the emergence of a workhorse actress who has developed her talent carefully and well. Sheedy started performing when she was 6. Her first gig was with the American Ballet at Lincoln Center. She wrote a children's book, "She Was Nice to Mice," at age 12. The book sold well. In her teens she continued to write, contributing to the Village Voice, The New York Times and Ms. Magazine, and worked off-Broadway and in TV commercials. After moving to L.A., she picked up roles in a few TV films and landed a recurring part on "Hill Street Blues." Then she popped up with the Brat Pack in the films we all remember, along with a few more we don't recall. Most recently she's published a book of poetry called "Yesterday I Saw the Sun," and in 1999 she was back on stage taking a risk, playing a German transsexual rock singer off-Broadway in the musical "Hedwig and the Angry Inch." She showed up in two independent films at the Sundance Film Festival two years ago, and she won Best Actress awards from the L.A. Film Critics Association, the National Society of Film Critics and the Independent Spirit Awards for her role in the film "High Art." She'll also be showing up soon in a guest-star role on HBO's controversial "Oz." TNT's "The Warden" is no "Oz," but it does put Sheedy smack in the middle of a dangerous maximum-security prison. Sheedy's role also puts the main burden of the film right on her shoulders. Sheedy plays Helen Hewitt, an assistant warden at a woman's prison in Washington state. Hewitt is tough and ambitious, two qualities Sheedy projects effortlessly. When a prisoner at a nearby all-male institution is killed during an inmate uprising he was convicted of molesting children and was universally despised by his fellow inmates Hewitt is called in as part of the investigative team. But instead of an honest effort to uncover the details of the murder, Hewitt finds she's part of an attempt to smooth things over. Encouraged by her mentor, a director of the prison system (Ron Rifkin), Hewitt follows her ambition and goes along to get along. However, when she's named interim warden of the all-male prison, her sense of professional responsibility returns in full force as she reopens the murder investigation. What she uncovers is a corrupt system that reaches far beyond the prison she controls. "The Warden" is not worth canceling dinner with friends. It may not even be worth learning how to program your VCR. But it is a decent story that manages to avoid the major obvious pitfalls, and it showcases Sheedy's considerable talents well. If you haven't seen Sheedy since she worked with the Brat Pack and you have some free time on your hands, "The Warden" will give you a good look at how well she's refined her resources during the intervening 16 years.