The title character never leaves the stage in the intense "Mary Stuart" that opened Friday at Shotgun Players' Ashby Stage. Even as Beth Wilmurt's conflicted Elizabeth worries over ordering her cousin and archrival's execution, and English lords plot on both sides, Stephanie Gularte's brooding Mary sits confined to a chair center stage - every twitch of her expressive face conveyed on three closed-circuit security screens above.

It's not just the videos and Christine Crook's sleek business suits that tell you this is far from the standard Friedrich Schiller drama that's ruled the stage for 210 years. Director Mark Jackson's radical adaptation is as stark, direct and unornamented as the corporate walls of Nina Ball's set, and as cruel as a conspirator's smile.

Jackson has stripped more than an hour, maybe a dozen characters and a lot of romanticism from Schiller's overstuffed text. What he's lost in terms of scope - the intricacies of political jockeying and the sense, so vivid in Carey Perloff's 1998 American Conservatory Theater staging, of kingdoms and religions at risk - he more than makes up for in the heightened immediacy of the psychological conflicts between and within Wilmurt and Gularte's English and deposed Scottish queens.

The essence of the broader stakes remains, with sharper currency, in the riveting verbal duels, plots and jockeying for power between Scott Coopwood's fierce but wavering Leicester, Peter Ruocco's true-believer radical Protestant Burleigh, bent on eradicating the Catholic Mary's claim to the English throne, and Ryan Tasker's creepily treacherous, Catholic fanatic Mortimer. John Mercer's muted moderate Shrewsbury and Jesse Caldwell as Mary's jailer provide able support, with Dara Yazdani as a flunky perilously caught in Elizabeth's defensive schemes.

A shocking splatter of gore, the startling appearance of a mirror, a stately transformation of Ball's set - Jackson uses everything, along with the surveillance videos and Jacob Petrie's slyly shifting lights, to enhance the focus on the queens. Wilmurt and Gularte respond in well-tuned dialogue and eloquent silences as they weigh their options and rue their decisions.

If Mary is the prisoner, Wilmurt balances that with an almost girlish vulnerability that barely masks Elizabeth's steely, at times peremptory, command. Gularte is simply magnetic, undergoing harsh treatment or arguing political points with a regal posture that defies her prison garb, then losing her poise to grasp at thin hopes. In one of Jackson's more harrowing innovations, she takes her own last confession with a passionate conviction that isn't altogether above suspicion.

It isn't Schiller. It's a thoroughly gripping modern political thriller.