Playwright: Paul Cosca. At: Brikenbrak Theatre Project at the Think Tank, 1770 W. Berteau Ave. Phone: 312-806-3506;$10. Runs through: Sept. 17

You never know what will be on the quiz, so you might want to take notes: Jacob Grimm is an overworked high school teacher struggling to guide his shallow students through the mysteries of Shakespeare and poetry in a small town far from PBS and Louder Than A Bomb. Sarah Riding is a precocious, but withdrawn, adolescent who wears a scarlet hoodie. Jake goes home to an agoraphobic wife. Sarah goes home to an abusive father. After a spontaneous two-voice recitation of T.S. Eliot’s “Love Song of J. Alfred Prufrock” in a deserted classroom one night, Sarah invites Jake to a rendezvous in the woods. The next morning, Jake returns to his house reeking of liquor, just in time to hear that Sarah has been found murdered at their trysting place.

If this were a rural-noir police procedural, the dramatic question would focus on the crime: Who did it? How did it happen? Who will discover the killer? Paul Cosca’s purpose is not a whodunit, however, but an existential study in which an innocent man riddled with suppressed guilt becomes so embroiled in the uncertainty engendered by this breakdown in the social order that he loses his ability to distinguish between truth and fantasy. (Aren’t you glad you took those notes?) As the speculations mount, our hero begins to see Sarah’s ghost, intruding Banquo-like at inopportune moments, and to despair of his peer support until his interrogation by the local sheriff is amplified into a full-blown CIA-torture scenario. Late in the story, Mrs. Grimm introduces a clue raising the possibility of this entire odyssey being a hallucination but, by then, we cannot help but suspect yet another red herring.

Cosca’s play exhibits all the hallmarks of a work still in progress, its improvisational tone heightened by the playwright also shouldering the role of the ambivalent Grimm. The production inaugurating Brikenbrak Theatre Project’s loft space on Ravenswood Alley is additionally encumbered with numerous set changes mandated by the script’s teleplay-ish structure, but a valiant ensemble of actors overcome their spartan surroundings to immerse us, both intellectually and emotionally, in our surrogate-Hamlet’s search for answers in a disorderly universe bereft of literary tidiness, where the facts may not even matter. What would it take to persuade Cosca to make his next effort a “Cold Case”-styled drama resolving the frustrating questions that continue haunt us weeks afterward?