Gay life either side of the liberationist divide is the self-evident topic of actor-turned-writer Alexi Kaye Campbell's highly accomplished debut play. But his real attentions are directed toward loneliness as it is experienced by three people with the same names separated by 50 years. The result covers some ground comparable to Nicholas de Jongh's Plague Over England, seen earlier this year, but with the Gielgud celebrity factor here replaced by two triangular relationships that bleed into and away from one another - and leave the audience at times aching, too.

In 1958 London, we first encounter the married estate agent, Philip (JJ Feild) as he enters into a four-month relationship with a well-travelled writer called Oliver, whom Bertie Carvel, in a riveting performance, plays with a smile that has clearly known its share of disappointment. Their burgeoning liaison makes a decidedly awkward outsider of Philip's wife, Sylvia, an onetime actress who brokered the men's meeting only to end up producing by way of carnal evidence a gold pen: Campbell's equivalent to the handkerchief in Othello.

The sublime Lyndsey Marshal trades in some decidedly clipped vowel sounds to then inhabit a different Sylvia in 2008: a Royal Shakespeare Company actress who has just landed the part of Viola at Stratford. This Sylvia is less cautious than her 1958 forbear, feistier, and very much in love with an unseen Italian by the name of Mario. That burgeoning relationship means that Sylvia could do without the demands made on both her time and emotions by the modern-day Oliver, a gay Daily Mail journalist addicted to anonymous sex. Ever on the prowl, Oliver nonetheless pines for the photographer, Feild's huskily spoken Philip, who has been driven away by his lover's promiscuity.

The director Jamie Lloyd follows his exceedingly smart, fleet reclamation of Pam Gems's Piaf with a more verbally hefty assignment that honours both the Rattigan-esque hommage of the 1958 sequences and the contemporary fear of intimacy encountered in the work of, say, Terrence McNally. Campbell, however, is his own man, not least in the triple challenge he throws the direction of Tim Steed, who plays all the other characters in The Pride. Steed gets a delicious visual gag early on as a fetish-prone rent boy and then a tumultuous second-act soliloquy, playing a blokish magazine editor who has his own "personal connection to the gay thing."

The Pride, meanwhile, makes all manner of connections of its own. Let's have more from Campbell, please, and soon.

-Matt Wolf