Daytona, Theatre Royal Haymarket

When Daytona was premiered at the Park Theatre last year some of the critics went into contortions to avoid giving away the two "reveals" in Oliver Cotton's plot. The challenge remains, but can there be many potential theatregoers who haven't heard about the shock revelation in the first half and the life-long secret disclosed in the second? If there are, the following may contain spoilers.

The premise is pretty conventional: an outsider enters and disrupts the humdrum life of the other characters. In this case, the newcomer is Billy, not a stranger but the estranged brother of Joe, with whom he hasn't been in contact for 30 years.

All three characters are Jewish immigrants, Holocaust survivors

It is New York in the 1980s and septuagenarians Joe and Elli have been together for more than four decades, sharing the kind of bickering but generally comfortable marriage which smacks of making the most of second-best. Their relationship is based less on remembered passion than on habit, friendship - and ballroom dancing. The action opens on the eve of a seniors competition they hope to win. Billy, who arrives unannounced when Elli is away at her sister's putting the finishing touches to a spangly dress for the occasion, tells Joe of an extraordinary action he has taken. In the second half Billy and Elli rake over shared memories.

All three characters are Jewish immigrants, Holocaust survivors. While on holiday at Daytona Beach in Florida, Billy has recognised a camp guard and, after observing him for several days, shot him dead in the swimming pool in front of hundreds of witnesses.

Cotton is dealing here with ways of coping with the past, disappointment in love as well as horror and loss. For 30 years Billy has denied his Jewish identity and experience, changing his name and even attending church with his wife's family. Nevertheless, given the opportunity, he exacts dramatic revenge. Cotton touches on important subjects: how to go on after life has been ripped apart, whether family obligations should remain whatever the history, whether taking violent revenge for dreadful cruelty can ever be a "good" action. But these questions are left on the periphery of the interplay between the three.

Maureen Lipman is gently moving as Elli, (pictured right with Oliver Cotton) especially when, remembering a period of devastating loss, her American accent slips into Mittel-European. Harry Shearer (the voice of Mr Burns in The Simpsons) as Joe and Oliver Cotton himself, who has joined the cast as Billy for the transfer, reach for less emotional depth but provide a bantering framework.

The whole plot is somewhat difficult to believe, but David Grindley's direction makes the most of the humour in imperfect relationships and Ben Stones's apartment set has the right lived-in, not-too-stylish feel.

Daytona may have seemed more daring in the intimate Park Theatre. In these grander surroundings it provides no more than a pleasant break from the throngs of summer tourists in Piccadilly. A pleasant break, however, which includes a rather touching effort at a nifty dance routine, a sequence which earned its own round of applause.

• Daytona at Theatre Royal Haymarket until 23 August