Even for a show about a family of undertakers, ''Six Feet Under'' may have struck some viewers as especially grim last season, ending with the unexplained disappearance and death of new mom Lisa (Lili Taylor) and the corresponding self-destructive spiral of her husband Nate (Peter Krause). But the coming fourth season, which debuts on HBO this June, won't be so grave, executive producer Alan Poul tells USA Today. ''Our intention is to return to the lighter, unpredictable tone of the first two seasons,'' he says.
Poul promises ''life-altering experiences and sexual experimentation'' for the extended Fisher family. That means an eclectic group of guest stars will be visiting the mortuary. (Warning: Spoilers ahead.) Already announced will be Mena Suvari (who reteams with series creator and ''American Beauty'' scribe Alan Ball), playing a rebellious art-school classmate of Claire's (Lauren Ambrose). ''Mena's character is a provocative performance artist and a strong feminist who doesn't care what anyone thinks,'' Poul says. Also joining the show will be ''Buffy the Vampire Slayer'' alumna Michelle Trachtenberg, playing a pop princess who hires Keith (Mathew St. Patrick) as a bodyguard. While Keith and David (Michael C. Hall) try to mend their rollercoaster relationship, he'll guard Trachtenberg's character as she visits ''The Ellen DeGeneres Show'' (the comedian/talk show host will play herself).
Returning guest stars will include Ben Foster (Russell, Claire's bisexual ex), Justin Theroux (Joe, the musician neighbor of Rachel Griffiths' Brenda, who'll compete with Brenda's ex-fiancé Nate for her affections), Kathy Bates (Bettina, the impish friend of Frances Conroy's Ruth), Patricia Clarkson (Ruth's bohemian sister Sarah), James Cromwell (Ruth's new husband George, whom she realizes she may have married too impulsively), and possibly Eric Balfour (Claire's presumed-dead boyfriend Gabriel).
Poul also promises that the show will keep up its trademark opening sequences of bizarre deaths of future Fisher clients, including one involving a sex toy. Can't wait.