In the face of religious persecution, government subterfuge and torture, what power does art have? That's the question in Bill Cain's post-9/11 masterpiece that filters terrorism paranoia through the lens of Jacobean London.

The notoriously cruel politician Robert Cecil (Matt Smith) wants William Shagspeare (Keith Cable) to write a play about how the government stopped the Gunpowder Plot. But Shag—the Bard in all but his name—knows that staging the government's propaganda will destroy his credibility with the groundlings. Not to mention the fact that a play about a bomb that doesn't go off spits in the eye of the very concept of dramatic tension.

Fitting of the name Equivocation, Shag uses tricks of rhetoric and staging to get around his dilemma. Post5's staging and cast perfectly match this flexibility. The set—two staircases flanking a balcony—serves as a courtroom, a jail cell, Shag's house and the Globe. Post5 newcomer Todd Van Voris switches deftly from the conspirator Father Henry Garnet to the blustering actor Richard Burbage. Smith's Cecil shifts from weary bureaucrat, to put-upon lackey, to a sadist. 

As is only appropriate of his last production, Post5 co-founder and artistic director Ty Boice steals the show (he's moving to Se—dry heave—attle). As Sharpe, the newest member of Shagspeare's company, he's a petulant prodigy. As King James, he's a terrifying Scottish jock lording over the nerds that are Shagspeare and Cecil. Perhaps his most stirring turn is as Gunpowder Plotter Thomas Wintour, whom Shagspeare finds tortured but unbroken, holding his arms so gingerly you can almost feel the rack.

At the play's center, Cable's Shagspeare possesses both the dignity of a theatrical mastermind and the helplessness of a guy trying to entertain people to save his neck. Where does he find power? The answer is deceptively simple: in the ability to tell the truth. 

SEE IT: Equivocation is at Post5 Theatre, 1666 SE Lambert St., 971-258-8584. 7:30 pm Fridays-Sundays through Oct. 4. $20.