Suspension, Old Vic Studio, Bristol

It's about time Mamma Mia! writer Catherine Johnson said "Here we go again," in her own new play: the hit musical and the irresistibly bonkers and enjoyable movie have occupied most of her last 10 years.

So she's returned to her career roots in Bristol with a tangy wedding day "local" comedy in the Old Vic, the first show since the building was controversially closed for refurbishment 18 months ago.

Not only that, she's joined the board and been instrumental with chairman Dick Penny – a local hero who runs the Watershed digital multi-media centre – in appointing Tom Morris of the National Theatre as the next artistic director.

This is all tremendous news, and it's nearly well bolstered by the play itself. Taking a nudge from Alan Ayckbourn's The Revengers' Tragedies, Johnson shows us one man trying to stop another from throwing himself off a bridge; in Ayckbourn, it was the Albert Bridge, here it's the Clifton Suspension Bridge in Bristol. Both men are excluded fathers: Dean (Stuart McLoughlin) from his young son's everyday life after his partner's gone off with a new boyfriend; Gerry (James Lailey) from his daughter's wedding which is happening within hailing distance. Gerry's in morning suit en route to make a protest when he tangles with the would-be suicide and they both end up handcuffed together singing "We Shall Not Be Moved" to the crowds below.

Meanwhile, in the honeymoon suite, Gerry's daughter Jemma and her blowzy mum, Anita (wonderful Louise Plowright, an original cast member of Mamma Mia!), are squabbling over the details of Gemma's fiance's children attending the ceremony. Confusingly at first, Dean's ex-partner Kelly (slinky Sasha Frost) is sunning herself in Spain while her mum back home, Kaye, a sluttish old drunk in Rosalind March's superb portrayal, is, ahem, babysitting.

You just know something's going to go horribly wrong and it does – three times over. There are two dead and one serious hospitalisation by the end, as the seeming time slips in the two separate stories catch up with each other.

Mamma Mia! was also about absent fathers, flawed women and an impatient, temperamental wannabe bride. Here, Johnson reveals much more of her old talent for surprising you with sympathy for the devil in all of us. As a single parent herself, she's still touchingly able to suggest that nobody's perfect and that the only real victims of all the bust-ups and blame-mongering are the children.

There are times when you want to bang a lot of heads together, especially in the drawn-out mother and daughter scenes in the hotel. And would a bride really go shopping on the big day itself? But Heather Williams's production has a striking, sometimes scary, vivacity, and Tim Goodchild's ludicrously ambitious design in the small studio builds a looming bridge over the troubled waters at ground level, where Nik Howden flits hilariously about as a pop-picking local deejay with live coverage of the "incident".

The two dads are played with a compelling, even soft-centred muscularity by McLoughlin and Lailey, and April Pearson is convincingly spoilt and stupid as the bride, squeezing in a sympathetic hospital visit in full slap and sequinned white gown between ceremony and reception.

Like the play, she is bursting out of her stays, saying nothing, while the play is saying too much, and not always in a well-ordered order.

To 28 March (0117-987 7877)