Playwright Steven Dietz sets one of his newest works, Yankee Tavern, in a dilapidated New York bar five years after the Sept. 11 attacks on the World Trade Center in 2001. When his father died of a questionable suicide, a young international studies grad student named Adam (Brian Vaughn) inherited the titular tavern, and now serves a clientele that seems composed exclusively of his dad’s old friend, Ray. Played by guest actor Will Zahrn, the aging barfly shares the gruff frustration of the late-George Carlin and delivers an unrelenting rant of conspiracy theories ranging from the staged moon landing and the JFK assassination to the 9/11 attacks.

While the arguments are compelling, Ray’s diatribes dominate the first half of the production, eclipsing the opportunity for Vaughn and guest actor Marti Gobel to create a subtle, genuine relationship between their respective characters, Adam and Janet, who are engaged. Making the most of a small ration of dialogue, Rep acting company member Torrey Hanson portrays a mysterious patron named Palmer with calm severity, an artistic choice that accentuates the weight of the information he shares with the other characters, information that reconstructs conspiracy as reality. While Yankee Tavern can be a challenge to follow, the play isn't really about what did or didn't happen; it's about the torment of uncertainty, a truth of life that all of us can relate to.

The Milwaukee Rep’s Yankee Tavern continues through Jan. 31 at the Quadracci Powerhouse Theater.