Scott Sheppard and Jennifer Kidwell in “Underground Railroad Game” (Ben Arons)

NEW YORK — Sometimes on the theater beat, you imagine you’ve heard and seen it all. And then along comes an evening like “Underground Railroad Game.”

This riveting, whip-smart performance piece, created by Philadelphia actors Jennifer Kidwell and Scott Sheppard, is as daringly unexpurgated as anything you’ll encounter onstage today. It’s an effort to reset the table for the complicated conversation about race that America eternally attempts to start, and always ends up recoiling from in guilt and insecurity and anger.

Actually, “reset” is too tame a characterization. What “Underground Railroad Game” does is flip the table over, tear the tablecloth to shreds and throw the dishes against the wall.

Kidwell and Sheppard remind us in this disturbing, discomfiting and disarming production — staged at off-Broadway’s Ars Nova with a mischievous zeal by director Taibi Magar — that we’re not even in the neighborhood of one nation under God. That we’ve never comprehensively and collectively undergone a reckoning with the toll of slavery and discrimination. And perhaps, one comes to feel, after 75 minutes of the play’s scathing satire, we never will.

“Underground Railroad Game” is a hall-of-mirrors excursion into the chasm that opens and closes and opens again between a pair of middle school teachers in suburban Pennsylvania, Kidwell’s Teacher Caroline and Sheppard’s Teacher Stuart. One imagines as the play begins that we’re in for a mock board-of-education-approved assembly, in which a pair of educators, one black, one white, addresses the audience as if we were a raucous group of preteens. The seeming topic is a state-sanctioned lesson on the Underground Railroad — the clandestine route by which enslaved people were helped to freedom by abolitionists — that will divide the students into two Civil War teams, one Blue, one Grey. The idea is they will participate in a weeks-long activity that simulates the railroad, with the goal of spiriting to freedom, or returning to slavery, some dolls hidden around the school.

That the premise is based on Sheppard’s own experience as a student in a Pennsylvania school in which just such an exercise took place adds a patina of authenticity to the activity. But this is a “game” in a larger sense, for “Underground Railroad” is an ever-evolving experience, in which the production is always one step ahead of us. To describe the metamorphosis in detail would be to cheat potential ticket buyers out of the pleasure of the show’s cascading sense of surprise. Suffice to say that the relationship between Teacher Caroline and Teacher Stuart becomes sexually and then racially charged, with the resulting carnal encounters — including some so graphic they leave nothing to the imagination — managing to reveal how ingrained our biases and resentments remain.

Kidwell and Sheppard are equally magnetic here and yes, truly brave. Along with their savvy director and designers, they play enthrallingly with dynamite.

Underground Railroad Game, by Jennifer Kidwell and Scott Sheppard. Directed by Taibi Magar. Set, Steven Dufula; lighting, Oona Curley; sound, Mikaal Sulaiman; fight choreography, Ryan Bourque; movement, David Neumann. About 75 minutes. Tickets, $50. Through Nov. 11 at Ars Nova, 511 W. 54th St., New York. Visit arsnovanyc.com.

Note: This version corrects an erroneous characterization of the experience Scott Sheppard had that inspired the play.