The illustrations are its most obvious idiosyncrasy. Cartoonist Ben Katchor, who also wrote the libretto, has drawn hundreds of images that provide almost every element of the set. For instance, when we meet GinGin (Jody Flader), a lonely New York twentysomething who lives in her father's penthouse, her room is a projected illustration, full of brightly colored, oddly shaped furniture.

But these are more than static images. When GinGin reaches for an actual phone, the screen behind her shows an animated hand reaching for an animated handset. Sometimes, the same drawing is projected on two different surfaces, as though a coffee shop or street corner were being echoed across the stage.

Katchor's beautifully rendered artwork gives the show an effortless magic, and it heightens the piece's major statement.

That's because the titular slug bearers are animated, too. We often see them tromping across an upstage screen, shoulders burdened with the small lead "slugs" they carry around the fictional Kayrol Island. We're told the slugs end up in almost every plastic appliance in our home. The weight of the metal inside, say, a blender, makes the object seem more substantial, even though its working parts are compact, light and cheap.

In other words, the developed Western world is a fantasy. Nothing we create is meant to last, so we have to exploit unseen people to keep ourselves grounded. Yet by abusing those laborers, we dehumanize them; we make them as flat as cartoons.

That's an unsettling paradox, and it's echoed throughout the plot. GinGin is desperate for a meaningful life, so like many do-gooders, she flees to Kayrol Island to live among the oppressed. However, as happy as the islanders are -- particularly the hunky Samson (Matt Pearson), the only flesh-and-blood slug bearer -- they could also be called brainwashed. By joining them, is GinGin liberating herself or just entering a new type of trap?

And what about Immanuel (Bobby Steggert), the Manhattan geek who wants to save the world but gets frustrated when he can't make the slug bearers share his love for reciting instruction manuals? When he retreats to his poetry club meetings, is he cutting himself off from truly living, or is he celebrating a culture of his own? Is isolation destructive, or is it valuable?

The show doesn't answer those questions, but it makes them fun to consider. Along with political urgency, the sung-through production provides an infectious soft-rock score, with music by Mark Mulcahy. Director Bob McGrath keeps the cast buoyant and sincere, which helps the show feel human, even among the cartoons.

Standouts include Peter Friedman as GinGin's sweetly clueless father, and Steggert, who convincingly conveys the joy of his unusual literary obsession.

But the real find is Flader, in her first major role. With her husky, folk-singer voice and her willingness to underplay moments most thesps would milk, she has the polish of a seasoned star. Her perf lends greater depth to an already rich experience.
 
Sets and projections, Jim Findlay, Jeff Sugg; costumes, Mattie Ullrich; lighting, Russell H. Champa; sound, David Arnold, Brett Jarvis; music supervisor, Randall Eng; production stage manager, Megan Smith. Opened Feb. 12, 2008. Reviewed Feb. 9. Running time: 1 HOUR, 40 MIN.