The most recent of this year’s revivals to mark Alan Ayckbourn’s 70th birthday, Private Fears in Public Places is a play that doesn’t join its dots. In short scenes, over 100 minutes, we follow six protagonists who lead overlapping but lonely London lives. And if it doesn’t quite cohere like Ayckbourn at his most revealing, well, disconnection is the theme. Secrets that you expect to become clear stay murky. Characters you expect to hook up stay separate.

I’m not convinced that everyone here quite belongs to 2004, when this was first performed — Ayckbourn’s computerless estate agents are a touch too square, his ex-Army boy is a shade too Young Edward Fox. But I also know that I would happily sit through another 100 minutes to find out more about characters whose frailties and frivolities are always convincingly human.

Laurie Sansom, the director, has retained half the cast from the Royal’s previous show, the excellent Just Between Ourselves. But he’s reinvented this proscenium-arch theatre as a studio space, seating us on the stage — on sofas, chairs, bar stools, floor cushions — while the action unfolds around us. So everywhere here is a public space: the bar where Christopher Harper’s depressed Dan, who left the Army under a cloud, sinks his sorrows with Kim Wall’s professionally personable barman Ambrose; the office where Stewart tries to figure out the incompatible extremes of Lucy Briers’s Charlotte — a fellow estate agent, a moralising Christian, a part-time carer and an S&M vixen; the loud bar where Dan goes on a blind date with Laura Doddington’s Imogen — where, in a brilliant piece of drunk acting, two strangers using fake names get falteringly intimate in a way that reminds us how little intimacy there is elsewhere in this show. Even the private homes are made public by the presence of audience members.

Ayckbourn’s thirtysomethings fear loneliness, yet also fear the exposure that closeness brings. The quietly excellent Wall suggests that the push-pull between the sense of captivity and the sense of purpose that Ambrose gets from caring for his abusive dad. Dan and Nicola grow apart through sheer lack of curiosity about each other. And if, sometimes, the depiction of lonely metropolitan life feels like a tentative stab at a familiar topic, Ayckbourn’s writing pulses with wit and empathy, even in its coarser moments.

With its burst of plaintive piano, with its issues left unresolved, this sometimes feels more like a film than a play — and indeed Alain Resnais, the French director, turned it into one in 2006. But we don’t need close-ups to feel that this excellent cast bring their characters to vivid life.

Box office: 01604 624811, to July 11

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