Walden review, Harold Pinter Theatre: Gemma Arterton is a Nasa architect in this compelling if flawed production

The debut play from Amy Berryman is ambitious, but ends up collapsing under the weight of its own ideas

Gemma Arterton (left) and Lydia Wilson as twin sisters Stella and Cassie (The Harold Pinter Theatre)

Walden makes for a compelling if flawed return to live theatre. American playwright Amy Berryman’s debut play is the opening piece in Sonia Friedman’s Re:Emerge season at the Harold Pinter Theatre, and it is admirable for Friedman to have programmed a season of new writing as opposed to a series of safe revivals. Walden is a big, ambitious play that ends up collapsing somewhat under the weight of its own ideas.

Some time in the not-too-distant future, astronaut Cassie (Lydia Wilson) returns to Earth after a year-long stint on the moon to stay with her estranged twin sister, Stella (Gemma Arterton), a former Nasa architect, who has begun a new life in the wilderness with climate activist Bryan (Fehinti Balogun). Cassie and Bryan are set up as diametrically opposed forces – one considers Earth beyond saving, and believes space exploration and habitation will be humanity’s salvation, while the other wishes to conserve the planet we have as much as possible, considering space to be yet another place for inequality and colonialism to thrive.

The conversations between them are sharp and energetic, zipping and bouncing off the walls of Rae Smith’s deliciously tactile cottage design. Berryman sidesteps anything overly didactic in these arguments; Cassie is ambivalent towards her mission and Bryan is disarmingly generous. Though Balogun, while a consistent pleasure to watch, is given short shrift with Bryan, whose tragic backstory feels a little shoehorned in, his narrative arc eventually sputtering out.