Dry Powder/Yous Two, Hampstead Theatre review - Hayley Atwell has competition

Sometimes it pays to come in under the radar.

By way of proof consider two simultaneous Hampstead Theatre premieres, one boasting star wattage courtesy Hayley Atwell fresh off TV's Howards End, the other a debut play from a young writer set entirely in a bathroom. (Yes, really.) And not for the first time, the less-heralded title, Georgia Christou's Yous Two ( ★★★★), knocks the English bow of Sarah Burgess's Off Broadway hit Dry Powder (★★) for six. Thank heavens this playhouse now allows critical coverage of their downstairs entries: Christou is too significant a talent, and Chelsea Walker's production in every way too fine, to go unheralded. 

I first saw Dry Powder nearly two years ago at New York's Public Theatre, where it generated immediate buzz by arriving with the director of Hamilton, of all shows, on board, and with a starry cast headed by Claire Danes, Hank Azaria, and an especially watchable John Krasinski. If, like me, your eyes glaze over at the very mention of high finance (there's a reason some of us are theatre critics), the New York run sold a sufficient sizzle that one barely had time to consider just how dry Burgess's writing indeed is. On a second viewing with a less glitzy local cast, not all of whom can handle the pronunciations required ("unprecedented" and "Maryland" both turn out to be tricky), one is aware of the gulf between the high-adrenalin morality tale that this school-of-Enron play may wish to be and its pro forma qualities as a play in thrall to the jargon of a world that it claims to despise.

The title refers not to cocaine, as some have assumed, but to available investment capital that allows these hell-for-leather moneymen (and women) to go about their business, heedless of the mere mortals who don't inhabit such heady financial climes. An often bewilderingly costumed Atwell plays Jenny, one of two private equity partners (a puppyish Tom Riley's Seth is the other) whose boss Rick (Aidan McArdle, pictured above with Atwell) is reeling from some dodgy personal PR. So this may or may not be the time to buy out a California-based suitcase company called Landmark that, Jenny argues, can be stripped bare and outsourced to Bangladesh. The marginally more enlightened Seth invokes the French Revolution by way of counter-argument and deployes phrases like "gender strength", while Andrew D Edwards's reflective set does its own dizzying dance towards the rear of the stage. 

The rarefied environs are what they are, and one has every confidence in Burgess's keen research. Less impressve is the strained repartee that often sounds like Noel Coward on a bad day, had the English master been interested in such things as GMAT scores and whether or not Toni Morrison is a novelist or a poet. (That last point of contention feels especially contrived.) The director, Anna Ledwich, has to struggle to floor the accelerator on a kind of slick, sleek venality that the New York cast inhabited with greater ease, but you can at least feel Burgess playing to her audience: a quip from Jenny about the merits (or not) of London in January got an all-too-empathetic laugh. 

Waste no time, meanwhile, in belting downstaits within the same building to savour the genuine charge that comes from a new writer with something to say and a team of collaborators who know how to facilitate her saying it. This is the second production I've seen from the (excellent) director Chelsea Walker (last year's Orange Tree entry Low Level Panic was the first) to begin with a central character having a long, lingering bath: quite whether this will become her directorial signature remains to be seen. 

The bather turns out to be a single father called Jonny (Joseph Thompson) who is interrupted mid-soak by his teenage daughter, Billie (Shannon Tarbet, pictured above), keen for a wee but also used to dealing with her dad across all manner of physical and emotional intimacies. Aspirational for a level of education and engagement with the world that her lippy dad can't really comprehend, the two ricochet off one another for 70 uninterrupted, deeply felt minutes. Billie along the way and against expectation becomes a mum, rendering her a young parent just as her dad was before her, and must thereby reckon with the possible inclusion of the child's father, the brilliantly named Fudge (Ali Barouti), as a new man in her all-too-circumscribed life. The ending poignantly suggests that Billie will go Jonny's way, except that she  is clearly too hard-wired for life's possibilities to while it away reclining in water. 

The play is at once subtle and smart about family dynamics: one notes before long the extent to which Billie keeps her dad on track, Jonny's way of expressing his gratitude by referring to the 16-year-old as Rocky or Rambo or simply "the boss". "You're the kid and I'm the grown-up," Jonny may rather too baldly announce, but we soon see the roles quietly reversed: Billie is the household strategist, handyman, and support system all in one.

The four-strong company, which includes Leah Harvey as a birthing partner for Billie who bails just when most needed, could not be bettered. Tarbet has played child-women before and here gently communicates a roiling intellect that won't be kept in check, while the altogether terrific Thompson laces Jonny's bravado with neatly flecked apprehension about the forbidding world outside. Barouti is never more moving than in expressing his unbridled delight at a parenting gig that has taken him very much by surprise, just as Christou's play itself makes an early bid to be this year's least anticipated theatrical delight. Don't miss it. 

• Dry Powder is at the Hampstead Theatre until 3 March
• Yous Two is at the Hampstead Downstairs until 24 Feb
• Read more theatre reviews on theartsdesk