"Euripides's Ion is never performed." So wrote Nicholas Wright in 1992, shortly before launching his own RSC revival with Jude Law. Now the play is back again, in a new version by Stephen Sharkey - and proves itself one of the most intriguing of all Greek dramas, a mix of family romance and political satire that left its mark on Wilde's The Importance of Being Earnest and Eliot's The Confidential Clerk.
Irony is the key to Euripides's masterpiece. We know from the start that Ion, a kind of Delphic Buttons who keeps the Temple of Apollo clean, was secretly fathered by the god and Creusa, now the Athenian queen. So when Creusa turns up at Delphi to cure apparent barrenness, we know it's only a matter of time before mother and son are reunited. In the interim, we watch with a kind of sadistic pleasure as first Creusa's husband Xuthus claims Ion as his own bastard son and Creusa then plots to kill the boy, thereby risking her own life.
Who created all this confusion? Clearly Apollo himself. And Sharkey's translation does everything to heighten Euripides's scepticism about divine intervention.
My only cavil is that the play's cynicism about power and succession is sufficiently modern not to need excessive underlining. But Sharkey is sometimes over-larky: when one of Creusa's attendants describes Bacchus "buckling his swash" we half expect Frankie Howerd to heave into view.
Yet this is not any old Ion, as Erica Whyman's fine production proves. Soutra Gilmour has designed an excellent set featuring a red path that snakes its way through the auditorium. And the balance between sentiment and satire is generally well preserved.
The first encounter between Sam Kenyon's wide-eyed Ion and Suzanna Hamilton's impressively sombre Creusa is deeply touching. He inquires: "You never had a child?" She replies: "God knows." I could have done without the interval, but this is a compelling revival that confirms Ion as not only the first tragi-comedy but also a classic piece of dramatic irony.
Until June 1. Box office: 020-7229 0706.