Enrique Murciano and Poppy Montgomery are busy doing what they do best: trying to solve a mystery. And there's a particularly nasty one unfolding here on the L.A. set of their hit CBS crime drama, Without a Trace, one that will heretofore be known as the Case of the Tighty Whities. Murciano has discovered a pair of cotton briefs not his own that are being used as set dressing on the soundstage, and he's gleefully flinging them around. Eventually, the soaring skivvies land on Montgomery's chair. ''Are those worn?!'' she asks, laughing but clearly grossed out. Murciano chuckles and graciously removes the questionable undergarments from Montgomery's personal space.
From the looks of things, you'd think this was the last day of school or maybe a raging party at the Sigma Nu house. But no, Murciano and company are just letting off steam at the end of an eight-day run spent filming Trace's emotional 100th episode (airing Oct. 29 at 10 p.m.), which follows Aaron and Sherise Gibbs (guest stars Eriq LaSalle and Lisa Gay Hamilton), a married couple who lived through the horrors of Hurricane Katrina only to have Aaron go missing a year later. Attempting to re-create the widespread devastation in New Orleans for the episode's flashback scenes is an incredibly ambitious undertaking, but nobody seems overwhelmed. While Trace has never been a flashy watercooler hit, it does have one of the most low-key working environments on TV: Production seems to hum along without ego, tantrums, or on-set drama. So aside from the ever-looming threat of underwear-related harassment, could starring on this below-the-radar (but top 15) series possibly be one of the best jobs in the industry? ''The truth is, I love the show,'' says Montgomery. ''I get to do work that I'm proud of.''
When Without a Trace premiered in September 2002, it had prime placement on CBS' schedule: 10 p.m. on Thursday nights, right after ratings monster CSI. Created by Hank Steinberg (The Nine) and boasting an executive producer named Jerry Bruckheimer, the show revolves around gruff investigator Jack Malone (Anthony LaPaglia), who leads a team of agents Samantha Spade (Montgomery), Vivian Johnson (Marianne Jean-Baptiste), Martin Fitzgerald (Eric Close), Danny Taylor (Murciano), and Elena Delgado (Roselyn Sanchez) on the hunt for missing persons. It's a solid formula, but in the beginning not everyone was confident that Trace a slower, more solemn show than most CBS procedurals at the time could build a fan base. Says LaPaglia: ''I saw the pilot and thought we were dead.''
But the series premiered to 16.2 million viewers, and by the end of the 2004-05 season when everyone appeared to be more focused on pratfalling housewives, horny surgery interns, and a country singer named Carrie Underwood it was quietly averaging a series high of 18.8 million viewers. Last year, it was TV's sixth-most-watched show, beating time-slot competitor ER in both total viewers and the adults 18-49 demo. Nonetheless, credit for its success and most of the media's attention has often gone to Trace's unstoppable former lead-in. ''It was always the perception that we were some kind of CSI clone,'' says LaPaglia. ''We lived in that shadow for a long time.'' Adds exec producer Jan Nash: ''Everybody [would love] to walk into a bar and [have] people go, 'Hey! You're on that hot, sexy show on CBS everybody's talking about!' But we've done very well, which is a testament to the work.'' LaPaglia's disciplined demeanor he's a study in quiet concentration on the set and the cast's genuine affection for their jobs help make this an enjoyably placid workplace. ''We've all realized how lucky we are,'' says Murciano. Alluding to the recent onset blowup between Grey's Anatomy stars Patrick Dempsey and Isaiah Washington, he adds, ''We're on a hit show why would I get in a fight with Eric?''
Speaking of Grey's, CBS swooped in to claim its Sundays-at-10 slot this fall when ABC's hit medical drama moved to Thursdays. ''We saw a chance to move in and pick up viewers,'' explains CBS Entertainment president Nina Tassler. ''And the numbers that have already come in have been great.'' That's a bit of an exaggeration: This season Trace is averaging 15.6 million viewers, down 16 percent from last year, due to tough competition from NBC's Sunday Night Football and ABC's Calista Flockhart soap Brothers & Sisters. (Still, the show ranks No. 2 in total viewers on Sunday nights, behind Desperate Housewives.) LaPaglia who's refreshingly blunt wasn't exactly thrilled with the schedule change, or with the way he heard about it. ''I was in France walking down the street,'' he recalls, ''and some guy said, 'Your show has been changed to Sunday in America.' I was like, 'Really? Wow. Thanks for telling me.' I'm not going to lie. I was not happy with the decision. Had we stayed on Thursday night, we would have held strong. At the same time, I understand it. Kind of.''
FOR THE LOYAL VIEWERS who have followed Trace to Sundays, the landmark 100th episode promises to be the drama's boldest outing yet. Warner Bros. gave the show a bigger budget to celebrate the milestone (an episode typically costs $2-3 million to produce), and the extra money went toward an elaborate and haunting sequence in which LaSalle paddles through post-Katrina New Orleans. ''We're always drawn toward stories about loss and atonement,'' says exec producer Greg Walker. ''This seemed like a story that was rich.'' Production designers built a series of roofs in a man-made lagoon on a Warner Bros. backlot, while other scenes were shot on an L.A. street with vintage buildings such as the dusty Gothic church seen in the episode's climax. ''It's important for the show to say something,'' says Jean-Baptiste. ''It's odd when TV shows set today are supposed to deal with everyday issues but don't mention things like Katrina.''
The way things are going, Without a Trace could be around for another 100 episodes' worth of smart, topical mysteries. LaPaglia is committed through 2010 (''Beyond that,'' he says, ''it would depend''), while Montgomery can't imagine life without her detective pals: ''Not having [the show] to go to every day would be heart-wrenching for me.'' Close a veteran of many short-lived series (Dark Skies, Now and Again) firmly believes that Trace's appeal has no shelf life. ''The audience responds to a sense of hope,'' he says. ''On our show, there's hope that someone is going to be found.'' Or at least that their underwear will be rightfully returned.