You're more likely to be awed than entertained by Matthew Sauer's ambitious new verse drama based on Arthurian legend. Sauer and director Jeff Harris of Riddlemark Theatre Company went back to an ancient Welsh text made up of numerous stories to stitch together this tale, centered on Guinevere and Lancelot's betrayal of King Arthur and the internecine conflicts raging at the time. Sauer's script, written in iambic pentameter, is generally cogent and forceful, the actors deliver it well, and the stage combat (choreographed by David Blixt) is exciting. But overall the play seems a literary exercise overloaded with exposition, and at almost three hours (with intermission) it wears out its welcome. Sauer can write; now he needs to learn how to edit. --Laura Molzahn a Through 2/25: Thu-Sat 7 PM, Sun 2 PM, Theatre Building Chicago, 1225 W. Belmont, 773-327-5252, $25.