In 1999, Mickle Maher asked Colm O'Reilly, one of the savviest fringe actors in Chicago, to be in his new two-character show for Theater Oobleck, An Apology for the Course and Outcome of Certain Events Delivered by Doctor John Faustus on This His Final Evening. Maher would play Faust, a skittish, self-aggrandizing schmuck facing his final hour on earth by delivering an extravagant, hilarious, and ultimately unnerving monologue about the sublime meaninglessness of nearly all human endeavors. O'Reilly would play Mephistopheles, Faust's implacable tormentor, and sit silent and motionless for the entire show. The gig was was harder than it sounds. "It was exhausting to do night after night," O'Reilly says, "trying to stay in a state where I'm a million miles away, where Faust is like a fly, where the character's sense of time and space—he's in hell, after all—is so vast." O'Reilly's stolid impenetrability was inexplicably mesmerizing, an exquisite foil to Maher's dazzling verbal gymnastics. For Oobleck's tenth anniversary remount, O'Reilly finally gets to make some noise, playing Faust to David Shapiro's Mephistopheles. "It'll be nice to move around at last," he says. Opens 9/25. Through 10/24, Chopin Theatre, 1543 W. Division, 773-347-1041, theateroobleck.com, $12, "more if you've got it, free if you're broke." —Justin Hayford.