The future comes before the past, or so goes a line in Alan Bennett's Forty Years On.

The play is really a series of loosely connected vignettes that romps through reminiscences of life around the first and second world wars, prismed through an ageing headmaster's final day in the job (played with a booming presence by John Hare in the main body of the piece and a pausing frailty in the prologue and epilogue).

He is assisted - or maybe thwarted - in presenting a school play prepared by Mr Franklin (his deputy and imminent replacement) and the ebullient arts master Mr Tempest. James McGarry and Stephen Picton live these two roles with conviction, creating sharply observed characters in the play-within-the-play; in fact they're probably too good to be teachers pretending to be actors.

Etta Geras as matron and Mel Sessions as Miss Nisbitt provide strong support, assisted by a troupe of young actors making up the rag tag school population.

This is not a play with answers, and that re-ordering of tenses and of (natural) order is at its heart. It poses questions on what it means to be England and the way that life changed in the twentieth century. It pokes fun and laughs at those traditions, while simultaneously sentimentalising them.

It is messy, disjointed and thoroughly confusing. But it is very well done, and in parts very funny - you just might leave not knowing whether you're coming or going.

Forty Years On continues at the Maddermarket Theatre in Norwich daily until April 23, except Sunday, with performance at 7.30pm and a 2.30pm matinee on April 23.