At the beginning of Palm Beach Dramaworks’ charming production of Lanford Wilson’s “Talley’s Folly,” St. Louis accountant Matt Friedman (Brian Wallace) explains to the audience that the ramshackle structure he’s standing in front of is a folly, the architectural name for a building that appears to have a specific purpose but is really mostly decorative.

But the most commonly known meaning of the term also applies in Wilson’s Pulitzer Prize-winning work, the second in the late playwright’s trilogy about the prominent small-town Missouri Talley’s. Friedman, a Jewish accountant, has returned to this crumbling boathouse to vigorously woo Protestant Sally Talley, who he romanced for a blissful long-ago week. Sally (Erin Joy Schmidt), who at 31 is considered both a spinster and the family disappointment, is just as vigorously trying to discourage him.

Both of them consider the other’s position to be folly - No-nonsense Sally believing that time, their differences and a particular secret history make a happy future together impossible. Meanwhile Matt, given to verbose soliloquies that barely mask either his passion or his nerves, believes that Sally’s resistance can be overcome by firmly refusing to take “no” for an answer.

Over the approximately 90-minute proceedings, director J. Barry Lewis guides his two leads through what becomes one extended conversation about expectation, disappointment and the folly of hope, the whole of which takes place in that crumbling, once-grand structure. As the two move about set designer Michael Amico’s stunning creation - you can almost smell the moss - they both hint at who they’d been during that idyllic stolen week, and reveal, in hesitant strokes, facets and facts the other couldn’t imagine.

Both Wallace and Schmidt adapt well to the physical constrictions of the play - watching a 90-minute real-time conversation might be incredibly tedious if you weren’t interested in both the conversants and the conversation. Wallace sells Friedman’s romanticism by selling the back story that grounds him, while Schmidt  inhabits a woman who is at once prematurely embittered and girlishly hesitant.

Occasionally, but only occasionally, they veer more caricature than character, playing Friedman’s nebbishness or Sally’s disappointed brittleness too literally. Otherwise, both actors are beautifully convincing as a couple whose connection, both past and present, hinges on belief in what might seem a folly. And they make you want to believe in it, too.