“Two Trains Running” is Penumbra director Lou Bellamy‘s latest production from August Wilson’s “20^th Century Cycle,” which chronicles the African-American experience, decade by decade, from 1899-2000. In 2007, Penumbra Theatre Company (a Knight Arts grantee) committed to producing each one of the cycle’s plays — and counting “Two Trains,” they’ve since completed six of them, roughly one play a year.

Here, Wilson directs his gaze to the cultural and political upheaval of the ’60s, but the iconic names of the Civil Rights movement — Malcolm X, the Black Panthers, Martin Luther King, Jr. — are only mentioned in passing. Rather, the playwright sets his sights on the lives of everyday folks caught in the undertow of that decade-in-flux: in this case, a motley assortment of regulars in a Hill District café, situated in a historically black neighborhood of Pittsburgh that’s quickly giving way to white gentrification.

The story’s lodestone is Memphis (played with just-checked fury by James Craven), a café owner being shaken down by city officials looking to buy his land out from under him, to demolish his café for the sake of new development. Also central are Risa, the wounded but feisty waitress of few words, and her ex-con suitor, Sterling, who’s struggling to turn over a new leaf. The ensemble is rounded out by a small-time numbers runner, a sage retiree, a well-to-do and roundly disliked neighborhood undertaker and Hambone, an emotionally scarred homeless man who acts as proxy for the injury and injustice done to generations of African-Americans.

In a 1999 interview for Paris Review, playwright August Wilson describes writing his plays backwards, beginning with a single line of dialogue from which he could get hints of plot, character, thematic elements. He recalls starting “Two Trains Running” with this line, spoken by the beleaguered restaurateur Memphis:

‘When I left out of Jackson I said I was gonna buy me a V-8 Ford and drive by Mr. Henry Ford’s house and honk the horn. If anybody come to the window, I was gonna wave. Then, I was going out and buy me a 30.06, come on back to Jackson and drive up to Mr. Stovall’s house and honk the horn. Only this time I wasn’t waving.’

Wilson goes on, “So I ask myself, ‘Who is talking? Who is he talking to? Who is Stovall? Why does he want to get a gun and go see him,’ etcetera. In answering the questions the play begins to emerge.”

It’s a revealing anecdote, because this production is plainly fueled by such conversational nuance between characters; and just as important in their exchanges are what’s left unsaid or what’s gotten at sideways. Indeed, Crystal Fox steals the show as the taciturn waitress Risa, and she does so with little more than significant glances, a deliberate, heel-clacking gait and consistently spot-on comic timing.

Like all the plays in this cycle, “Two Trains” is an intellectually meaty show, satisfying for its literary accomplishment and sense of history, not to mention its impressive execution on Penumbra’s stage. But its three hours go by surprisingly quickly — because the characters are so engaging and their stories so compelling as they unfold. The subject matter is serious, absolutely — but the play itself? In Penumbra’s hands, it’s really fun to watch, too.

“Two Trains Running,” written by August Wilson and directed by Lou Bellamy, is on stage through Oct. 30 at Penumbra Theatre, 270 North Kent St., St Paul, Minn., 55102. Box office phone: 651-224-3180.