Toni Collette plays man, woman, and child in United States of Tara.

It happens. There are shows that aren’t as good as their actors. And yet we watch because the actors are so very good. This is the case with Showtime’s half-hour dramedy United States of Tara, which comes to you from no less than executive producer Steven Spielberg and creator Diablo Cody (of Juno fame). Cody’s aggressively quirky imprint is unmistakable, for better but mostly for worse. The draw is Toni Collette as Tara, a married, suburban artist who suffers from Dissociative Identity Disorder (a.k.a. Multiple Personality Disorder), a condition that allows the Australian actress to have her mesmerizing way with three additional, radically diverse “alters”: a raunchy, beer-guzzling Vietnam vet; an obnoxious 15-year-old kleptomaniac; and a prim Betty Crocker housewife.

“Ultimately it’s about mental illness, told with an incredible amount of empathy for D.I.D.,” says Collette, who has the same jones for warts-and-all that other actresses have for Botox. Though she cleans up nice (see the photo above), she has, since her breakout role in Muriel’s Wedding, devoted much of her career to animating wallflowers, frumpy mothers, and disagreeable misfits (In Her Shoes, About a Boy, Little Miss Sunshine, her Oscar-nominated role in The Sixth Sense). Crooked teeth, gaining weight, (really) unflattering clothing—bring it on. “I’m a naturalist,” she says. “Part of being an actor is representing the human race. I’d rather represent the realities of it.”