Zach Theatre's Heisenberg

Harvey Guion and Liz Beckham in Heisenberg

It's unusual, I imagine, for a theatre review to begin with an explanation of Heisenberg's Uncertainty Principle; nevertheless, here we are. In a very dim nutshell, German scientist Werner Heisenberg determined that an act as seemingly innocuous as observation still comes with a tangible force capable of affecting the behavior of quantum particles, though in what way it's impossible to predict. It's related to the Observer Effect and the "Copenhagen Interpretation" of quantum physics – but Observer isn't really an interesting play title, and, well, Michael Frayn already wrote Copenhagen.

In Simon Stephens' Heisenberg, currently at Zach's Kleberg Stage, a case could be made that we, the audience, are the observers, and the two characters a force unto each other. Uncertainty certainly reigns in this well-written, precisely directed, and superbly performed piece. It's a loose connection between title and subject, sure, and the scientist's name is never spoken, but as we watch a charming and unlikely May-December romance blossom in the strangest of ways, we're left to assume the cat is both alive and dead until we reach a definite conclusion (wait ... dammit, that's Schrödinger).

We begin moments after Georgie plants a smooch on the back of Alex's neck in a London train station, thinking he was someone else, and the apologetic frenzy that ensues. The unlikely (or is it?) relationship progresses rather quickly, their contrasting personalities challenging each other in compelling ways. Georgie is a curious woman: direct, aggressive, frantically kinetic, and a bit vulgar – perhaps characteristics an English playwright might ascribe to all American women? This could easily be problematic, but Liz Beckham expertly navigates the character with incredible skill and authenticity; her Georgie seems almost like a reformed "manic pixie dream girl" with whom life has had its unkind way and has learned more than her share of hard lessons by her early 40s. Harvey Guion's Alex is the direct opposite: reserved and concise, if not a bit withdrawn. Alex is a 75-year-old butcher, and Guion treats the character with deserved patience; the result is as charming as it is entertaining.

This is one of those "too many details spoil the plot" type of shows, so I won't let any cats out of their bags (or boxes). Suffice to say, it's not your typical rom-com. It's not even typical fare for Zach Theatre, in my experience; produced in the round with minimal design, this two-hander stands in stark contrast to such large-scale Zach offerings as, say, Sunday in the Park With George or Disney's Beauty and the Beast.

The set by designer Scott Groh is just two chairs and one table on a bare stage, with Guion and Beckham acting as stagehands as well. Craig Brock's sound is lovely, providing distraction during scene changes and environmental ambience. The costumes by Blair Hurry are modern-day, which costumers around the world know can often be as difficult as anything. Rachel Atkinson's lights are simple but effective. Amanda Cooley Davis provides dialect coaching, and here's the one place things get murky. It's hard to place Guion's accent, which seems to slip between RP English and Irish, sometimes both, and sometimes neither. We do learn roughly one-third through the play that Alex was born in Ireland and came to London at 11, so it's possible they were going for a hybrid, but it's not quite spot-on and is the one part of the show I found distracting – though only just.

Director Nat Miller does a remarkable job bringing the story to the forefront and allowing the actors to shine, while not forgoing design, just keeping it artistically simple and elegant. Heisenberg is a show about risk and change, really, and the "uncertainty" that comes with actively taking those risks, without a clue what life will yield as a result.

Observe for yourself. I think it's worth it.

Heisenberg