Jesse L. Martin as Detective Ed Green by Virginia Sherwood/NBC Photo
The least that a key team player can expect when his (or her) time comes to depart the unstoppable Law & Order is a memorable farewell. No slinking off into the sunset for Jesse L. Martin. No "Is this because I'm a lesbian?" nonsense, as befitted the hapless Elisabeth Rohm (arguably the most inept cast member in its 18-season history). Martin's character of Ed Green, who bridges the past as the last detective to serve alongside the late Jerry Orbach's legendary Lenny Briscoe, hangs it up tonight in a powerful episode that unearths some disturbing secrets- at least one harking back to how he coped with losing his partner- behind Green's typically professional demeanor.

I'm truly sorry to see Martin go at this juncture of the show's history. After a number of seasons of uneven cast chemistry- I pretty much bailed during the "dark years" of Rohm, Fred Thompson and even Dennis Farina (who seemed too much like a "TV character" for my taste)- this season righted itself with the strong additions of Jeremy Sisto as Green's new partner, the war-haunted Cyrus Lupo, and Linus Roache as scrappy new ADA Michael Cutter, working under the often dubious supervision of newly promoted DA Jack Mc Coy (Sam Waterston). The show, which even in its off years was never less than intelligent and compelling, has felt newly re-energized of late, and it's too bad we couldn't have enjoyed at least one full season of the refreshed stability.

But it's now Martin's turn to go through Law & Order's notorious revolving door, which leaves us, rather remarkably, with a core cast that's comprised half of freshman newbies: Sisto, Roache and K-Ville refugee Anthony Anderson (who appears tonight as an Internal Affairs cop itching to move to the other side) joining long-timers Waterston and S. Epatha Merkerson as well as Alana De La Garza, who's only in her second season as ADA Connie Rubirosa. This may help account for Law & Order's longevity. The franchise is the star, and while the actual costars may not exactly be expendable, they are replaceable, though not always with actors of equal merit. (It may be a while before we can gauge Anderson's suitability, as there will undoubtedly be tension in inviting a former Internal Affair rat into the mix before his character of Kevin Bernard comfortably fits in.)

Martin's many fans can take some solace in the fact that he has been given a strong showcase in his final case, which at first appears to be a routine murder of a man in the wrong place at the wrong time. Green's in good humor, joking with his partner and his boss, until the victim's gambling past intersects with skeletons in Green's own closet. The case takes an even darker twist that puts the detective in the crosshairs of Internal Affairs and a possible grand jury indictment. As the story plays out, it becomes evident just how much everyone in the precinct and the prosecutor's office wants things to go right for their friend. "We thought you were worth saving," Cutter says at one point. It's a fitting tribute to a fine actor, a strong character and a durable show that will honor him by continuing to do its job for the foreseeable future.