One of last year's theater highlights was Our Shoes Are Red/The Performance Lab's production of Will Eno's Oh, the Humanity. That show was one of those rare instances of live performance transcending entertainment to become something more appropriately characterized as "art." (There's nothing wrong with entertainment, of course. But a little art every once in a while is nice, too.)

The Lab is an amorphous group of theater artists from around the country, based—for the last five years—in Portland, where Artistic Director Devon Allen makes her home. The Lab differs from other theater companies in several key respects. First, they're a company without a season—their (infrequent) performance roster is determined not by a fixed calendar schedule, but by how long each individual show requires. As Allen pointed out during our interview, the same process won't necessarily work for different shows—some material benefits from a lengthy, thorough rehearsal process, while other scripts might be better served by a process that preserves spontaneity and freshness. Logistics aside, though, the element most crucial to the Lab's work is that, as Allen put it, "Everyone working on the material loves the material."

Which brings us neatly to the Lab's newest show: The Portland premiere of An Oak Tree.

An Oak Tree is written by Tim Crouch, whom diligent followers of local performance may remember from his 2008 appearance at PICA's Time-Based Art festival. Crouch's TBA show, England, was an intelligently constructed piece of performance-inside-performance: Set in an art gallery, the show cleverly explored the arbitrary nature of value—emotional and monetary—in regards to both life and art.

Like England, An Oak Tree uses an unconventional structure to get at deeper ideas about the nature of performance. The play has two characters, the Hypnotist and the Father. The Hypnotist is played here by Dennis Kelly; the Father—here's the hook—is played by a different actor every night. As a guest in the Hypnotist's act, the actor playing the Father is guided through the unfamiliar script by the Hypnotist, whose showmanship and presentational skills are operating on multiple levels.

"I chose the play for Dennis," Allen told me. "He has a kind of style about him that's almost from another time. He's a great showman, yet at the same time he has the sensitivity to go to interior places—a lot of actors can't do that."

During runs in New York and LA, the role of the Father has been played by such notables as Mike Myers, Francis McDormand, and Lili Taylor (women frequently play the role). The queue for the Portland show is less star-studded but still impressive, and includes Hand2Mouth's Erin Leddy, Third Rail's Stephanie Gaslin, and Drammy winner Garland Lyons. The walk-in actors are unfamiliar with the script, but nothing about An Oak Tree is improvised; it's tightly controlled by the Hypnotist, with the only real variable being what each individual actor brings to the role. It's an intriguing premise, and one that aligns nicely with the Performance Lab's history of work that 's emotionally engaging and intellectually rigorous.