KEEPING A diary, as Gwendolen remarks in The Importance of Being Earnest, is essential. "One should always have something sensational to read in the train." Most people's diary entries, however, degenerate to weather reports. When Walker (Colin Firth) discovers his late father's secret journal, he and his sister Nan (Elizabeth McGovern) are disappointed to see that the very first entry is shockingly bland: "Three days of rain".
For the siblings, this comes as something of an end, but for the playwright Richard Greenberg it is a cunningly constructed beginning. This, the last in the Donmar's American season, is an often fascinating study of the legacy of two architects whose family home is a world-renowned landmark and the centre of an emotional whirlpool for their children.
The sibling rivalries of the well-layered characters are deftly established as Nan meets up with neurotic Walker for the reading of the will. She's furious with him for having disappeared for months, leaving her to deal with their father's death and their helplessly airy mother, wittily described as "Zelda Fitzgerald's less sane sister". Complicating matters is Pip (David Morrissey), son of Ned's partner Theo and former lover of the now-married Nan. Walker's realisation that he has been partially disinherited triggers old jealousies. Then, at the climax of the first act, he dramatically puts the lid on the past. "God damn you," cries Nan, "Now we'll never know anything."
We, however, quickly learn much more as the second act cuts back to the time of the diary to reveal the unwritten truth. The same actors now play their parents, filling the stage with correspondences through the years. Pinter reversed the action in Betrayal, and Kaufman & Hart played a similar game in 1934 in Merrily We Roll Along, but Greenberg's twist cleverly explores the idea of the sins of the father.
The director, Robin Lefevre, coaxes witty, beautifully modulated performances from his cast, all of whom resist the temptation to signal too heavily what we know of their older selves. The rivalry between the men is captivatingly done and the climactic seduction scene is exquisitely played by a wonderfully gauche, stammering Firth - all spectacles and hunched shoulders - and febrile, skittish McGovern - a headstrong cross between a young Katharine Hepburn and early Blanche Dubois - yet even they cannot stave off the curiously flat denouement.
The gap between what we thought we knew and the literal truth widens throughout in the manner of a well-crafted thriller, but the play falls victim to its neatness. Greenberg displays enviable talent, not least for piquant dialogue, but ultimately you're left feeling that the play is more contrived than emotionally resonant.
To 13 Mar (0171-369 1732)