ER. 10 p.m. tomorrow, Channel 10.

NBC'S "ER" marks its 300th episode tomorrow night, and I'm happy to report that nothing explodes.

None of the regulars is killed or maimed and County General is neither quarantined for a suspected outbreak of Ebola nor attacked by terrorists.

Sweeps is over.

Instead, "300 Patients" is a relatively quiet (by "ER" standards) episode that advances a continuing storyline, tells a poignant story about a dying patient and her family and demonstrates, possibly for the 300th time, that Morris (Scott Grimes) is actually a 12-year-old boy in a medical coat.

That might not seem remarkable at Seattle Grace, the "Grey's Anatomy" hospital staffed almost entirely by junior high school students, but County General is a place where patients mostly get put first, even when their doctors are really bummed or even really horny.

So Morris, who I'll admit has progressed professionally, and even a bit personally, since Grimes joined the cast in 2003, is still there for comic relief.

And that's perhaps not a bad idea, given that much of the episode is devoted to Abby (Maura Tierney) and her continuing downward spiral.

Tierney's take on Abby's alcoholic relapse has been utterly believable - I'd give her the Emmy right now, just for her willingness to play such an exasperating character - but fun it's not.

"ER's" weathered more than its share of not-fun in the past 13 1/2 seasons, but you don't get to Season 14 without learning to strike a balance.

You also don't get this far without relinquishing the possibility of giving people something to talk about every week. "ER" may once have been a water-cooler show, back in the George Clooney wonder years, but now it's closer to the medical equivalent of "Law & Order," and it's Patrick Dempsey's McDreamy who gets the buzz.

Meanwhile, people come and go, just as they do in a real emergency room. Though I've been watching it more this season than I have in several years, I couldn't, for instance, tell you exactly what "24's" Reiko Aylesworth is doing there (other than sleeping with John Stamos' character), but as long as she doesn't start killing patients, I'm not concerned.

"ER" may be a more honest show now than it was in its heyday, having morphed from a thrill ride into a workplace drama where the workplace itself has become the star.

But is that enough to justify a 400th episode?

Probably not.

'Life' not short

on answers

It's hard to imagine NBC's "Life" (10 p.m., Channel 10) making it to a 300th episode, unless Detective Charlie Crews (Damian Lewis) slows way down.

As if.

"Life's" writers prefer life in the fast lane, which is why this week's two-parter ends tonight by solving a big piece of the mystery surrounding Crews' unfortunate 12-year incarceration.

It's not totally wrapped - hey, it's not even Christmas yet - but anyone who's complained in recent seasons about being strung along by serials that took too long to get to the prize inside might want to check out "Life."

Correction

In yesterday's column, I misidentified "Late Show with David Letterman" writer Bill Scheft as the show's head writer in an item about the writers' strike Web site, LateShowWriterson

Strike.com.

Eric Stangel and his brother, Justin Stangel, are the show's head writers. *

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