What they didn't teach you

You don't have to wear the right old-school tie to enjoy the best of the latest offerings on the London Fringe.

In Iona Rain (Croydon Warehouse), Peter Moffat has written that most dangerous of things: a public-school play. Once, four boys shared a life at their African boarding school. Now in their thirties, they meet once more on Iona. It's dangerous in the sense that a work with even a whiff of dorms and beatings and homoerotic ragging risks alienating a good part of its audience before it starts - something that in this case would be a crying shame. Because Iona Rain is a beautifully crafted new work (no sniggers, please, it won Croydon's 1995 International Playwriting Competition), understatedly written, acted and directed. I can only urge both public-school phobics, and Londoners who go rigid at the thought of trekking out to Croydon, to see it before it ends on Sunday.

If you had to compare Moffat, a criminal defence barrister by profession, with another writer, then it would be Simon Gray. True, he doesn't have Gray's savage wit - for all the simmering unpleasantness that underpins its action, Iona Rain is a gentler play than either, say, The Common Pursuit or Quartermaine's Terms - but Moffat does have a similar ear for the language of the emotionally crippled middle-class male shipwrecked by the siren song of nostalgia. It's not quite that none of the characters has made a life for themselves after school. They've tried. Take Bruno, who for reasons best known to himself has organised this strange summer holiday. He's got married, fallen in love, flirted with Catholicism, and become (we're led to believe) some kind of spy. But when the chips are down, after his wife dies in childbirth and he loses his faith, it's to his old school companions he turns.

And I use the word "companions" advisedly; this is no Peter's Friends- style knees-up. Psychologists talk about Helsinki syndrome, the deep bond that often grows up between captor and hostage. The relationships in Iona Rain owe something to that. At school, Bruno and Michael were the captors, and now they reminisce with guilty glee about their adolescent sadism. Their hostages were Mouse and George: the former now a pederastic priest, the latter his transvestite lover (more Hyacinth Bucket than Ru Paul).

Paedophilia, espionage, cross-dressing and childhood guilt make a fruity mix - imagine the possibilities for Oprah-style psychobabble. It's to Moffat's credit, then, that he's written a play that is never less than believable, and one that eschews big emotional set-pieces for something subtler, woven into the fabric of the writing.

Moffat's dialogue is tremendous: sparse but rich, elliptical without being unnecessarily obscure. And never better than in the banter that still unites Bruno and Michael, a lingo in which a condom becomes a "seedcatcher", while Rome is "Pope Town". "I think wit is an overrated virtue," says Michael's barrister wife, Anne. "Men use it to control the conversation." Along with so much else, Iona Rain elegantly demonstrates the truth of that bitter assertion.

If Peter Moffat bears comparison with Simon Gray, Ellen Dryden - it has been said - is a bit like David Hare. I'm not sure, though, that her ambitious new play The Power of the Dog (Orange Tree, Richmond) quite pulls off that Hare-ish trick of making the minutiae of middle-class life seem somehow symbolic of the state of the nation. Vivien, the deputy head at a London comprehensive, is facing two problems. First there's her mother, Grace (the outstanding Barbara Lott), who has recently had a stroke, and is being looked after by Vivien's pious old aunt, Vera. Second, there's Lisa, a brilliant yet delinquent pupil, whom Vivien has been teaching English after school for six years, the kind of child who quotes Browning when she wants to be snide. The point is that Vivien is a "snow queen" - unable fully to engage herself with either her mother or her pupil - and as Richard (the excellent James Kerr), a firebrand young teacher points out, if you put up ice barriers people will come at you with their ice-picks. Dryden is very good at conjuring up a world of Range Rovers and Joanna Trollope, barbed gentility and machinations over relatives' wills. But the two plot strands never really dovetail, and Lisa remains too much of a cipher to illuminate the family dealings (she reminded me of one of those identikit adolescents who crop up in every other episode of Inspector Morse).

More family grief in Judy Upton's new play Sunspots (Red Room, Kentish Town). Twentysomething Aimee visits her sister Pola in Hastings. Aimee is about to leave for Cyprus with her fiance, Sam, an older man and a travel agent to boot. Pola - who is squatting in an amusement arcade and spends most of her life "tagging" buildings with spray cans - has been sectioned in the past. Not surprisingly, she and the conservative Sam hate each other from the off. So when Sam has a catatonic fit, the battle begins for Aimee's soul: will she choose her dull-as-ditchwater lover or her crazy sister?

Sunspots is a difficult, resolutely unschematic play. If you're the kind of person who likes to have some idea what a play is "saying" when you come out, you'll find it maddeningly frustrating. But there are good things here, in the text as well as the performances. Upton's a playful writer who likes nothing better than to upset expectations. To take a tiny example, it's straight Aimee not drop-out Pola who believes in the power of crystals to heal. And that contrariness is true of the plot, too. You thought this was a tale of redemption through illness, or self-discovery through sex. Think again - because Upton has an agenda of her own and, though you may not have the foggiest what it is, at least it's not the cliche you feared.

n 'Iona Rain' (0181-680 4060); 'The Power of the Dog' (0181-940 3633); 'Sunspots' (0171-813 9653)