''The Underpants," Steve Martin's adaptation of Carl Sternheim's 1910 comedy that opens in previews tonight at the Lyric Stage Company, is routinely billed as ''hilarious," ''laugh-out-loud funny," ''sidesplitting," and so forth. Naturally, that's an actor's nightmare.
''We get those 'laugh-out-loud-funny' headlines and think, 'We can't possibly live up to that,' " says Caroline Lawton, who makes her Lyric debut as Louise, the mild-mannered housewife whose wardrobe malfunction -- an inadvertently exposed pair of pantaloons at a military parade -- sets the farcical plot in motion. ''But we've been laughing all the way through rehearsals," she says. ''It's fantastic."
Lawton, whose performance in last summer's ''Arcadia" at the Publick Theatre was widely praised, is quick to credit her colleagues in ''The Underpants" -- Steven Barkhimer, Stephanie Clayman, Lewis D. Wheeler, and Neil A. Casey among them -- with finding the comic nuances in every line. ''Everything kind of spins off of Louise's character, who's really this straight man," she says. ''Everybody is insane around her."
Lawton notes that she didn't really train in comedy; her background was in Shakespeare and Greek tragedy. ''I really had never done comedy until I was cast in 'Shear Madness,' " she says.
But the long-running, crowd-pleasing antics of ''Madness," she says, proved to be ''great training" in comedy technique. ''And I'm still trying to bring that same idea in from drama: play for the highest stakes possible," Lawton says. ''It's comedy to everyone else, but it's still tragedy to the character."
Indeed, Martin's adaptation, while maintaining the farcical character of the original, also uses it to touch on a potentially deeper contemporary theme: the fleetingness of fame. When Louise's undergarments bring her temporary celebrity, she becomes, Lawton says, a kind of ''1900 Real World" reality-TV participant. ''You get that momentary glimpse of fame, and it's so elusive, and you mourn it, and you wish it would come back."
It doesn't, of course. And that's funny.
Daniel Gidron directs ''The Underpants" at the Lyric Stage Company, 140 Clarendon St., through Feb. 4. Tickets, $20-45, 617-585-5678 (a new phone number); www.lyricstage.com.
For tickets, $10-$42.50, call 617-933-8600 or visit www.bostontheatrescene.com.
Steven Maler of Commonwealth Shakespeare Company will direct. The series continues with readings of Lorraine Hansberry's ''A Raisin in the Sun" on Feb. 27 and Tennessee Williams's ''The Night of the Iguana" on March 13. Tickets, $5-10, 800-447-7400; www.wangcenter.org.
Louise Kennedy can be reached at firstname.lastname@example.org.