It makes perfect sense that a theater company whose current renovations will include a new space to be christened “the Cradle” would commission a play about motherhood in all its forms. Karen Zacarias’s “Legacy of Light,” at Arena Stage in Crystal City now through June 14, is a wide embrace of these themes – the purely physical act, the creative endeavor, even the scientific genesis. Maybe too wide an embrace. Its first act had me a bit impatient. But if you can get through the beginning exposition and make it to the second act, you’re rewarded with some truly funny and poignant moments that bring these themes to life.

The production weaves together two sets of couples – in the past, scientist Emilie de Chatelet works furiously on her thesis while balancing a young lover, a longtime companion (who just happens to be Voltaire), a military husband, and a fiesty daughter who shows more interest in fashion than learning. In the present, scientist Olivia struggles to come to terms with balancing the impending birth of her child by a surrogate mother while investigating the more exciting birth of a star in a distant galaxy.

You could say these two have a lot on their plates.

The first act plays with mutable gender roles – both the young male lover in the past and the modern husband register as rather feminine (not to mention, a tad annoying), while the women read masculine at least in terms of their assertiveness and consuming drive. It’s a conceit that gets turned on its head in the second act, when timelines intersect and traditional roles become harder to ignore.

Several audience members were remarking at intermission that they had no one to root for, no engaging protagonist. I disagree. Voltaire emerges as the leader in the first act, but is this merely because he is an engaging life force in reality, one that a playwright cannot help but flesh out, rather than a testimony to the play itself? Hard to say.

Clear acting standouts are the incandescent Lise Bruneau as Emilie de Chatelet and waggish Stephen Schnetzer as Voltaire. Whenever they are on the stage it brightens. Carla Harting as Olivia nailed a beautiful opening monologue in the second act and brings both the struggle and the union between scientific mind and heart perfectly to the fore throughout. Michael Russotto has the most thankless task of bringing the modern beta male Peter to excruciating life while then easily transitioning to the more alpha Marquis in the past. The moment when he and Voltaire as the two old lions face off and vanquish the annoying young puppy lover was a highlight.

Lindsey Kyler and David Covington as the modern brother and sister confused me with their beautifully dulcet drama school tones. These are kids down on their luck in New Jersey. Was it a directorial choice not to rough them up slightly vocally or even physically? Everything was so bright about these two – bright, young, cute. I don’t doubt the actors’ sincerity or talent but the characters completely unmoved me.

All plotlines are neatly tied up in the end in an homage to 18th century dramatic conceits. I found myself being won over, though I also felt mildly manipulated and couldn’t quite settle on the reasons why. Perhaps I personally am just not touched by the overall themes of motherhood work/life balance. But if you are a professional woman struggling with those issues, no doubt this will be the play to see for you, and in that case, bring tissues. There is an underlying sadness and inevitability here – life goes on despite our dreams for more.

Now through June 14 at Arena Stage’s Crystal City location
Tickets: online at www.arenastage.org
by phone at (202) 488-3300
in person at the Arena Stage Sales Office
1800 S. Bell Street
Arlington, VA 22202