In Seiriol Davies' debut play Moon River, a cast with a wide age range play the inhabitants of and visitors to a nursing home. The piece is moody and poetic, eschewing naturalism for a deeper insight into what it's like to grow old, and the result is really quite sad. There's nothing wrong with the piece, I'd just have hoped that growing old was slightly less depressing.

Moon River, according to the programme notes, was written after a writer on an assignment spent a lot of time with the elderly, and it's not hard to believe that this play, while not necessarily verbatim, is certainly very close to life. The piece doesn't really follow a plot - loosely, we focus on Gladys, who tries to control the others as she herself seems to lose her mental faculties. But this is an emsemble piece, and we're given a number of characters embodying the classic 'elderly' stereotypes: Sandy, Home Counties and still fairly with it; her husband Ron, who is slowly going deaf; Ingrid, always drinking and laughing; Mary, randy and talkative; Frank and his Zimmer frame; and the almost immobile and mute Esther.

As a slice of life, it's endearing most of the time - these characters are all very believable despite bordering on the caricature, and are played with love and care by the performers of varying ages. It's particularly nice to see the mix of ages - a novel approach to a play about the elderly, although casting the oldest and most immobile as the youngest performer did hint at her chance to break out of her shell. The problem is that this more comic backdrop is then painted over with moments where the tone shifts into the difficult and tragic. Gladys recounting being raped (and, potentially, losing her mind completely), the entire cast going into the garden to sing Moon River, and the moment that Esther suddenly gets the chance to be a romantic heroine just one last time... These moments are tenderly played, but they just don't fit with the jokey tone of the previous scenes.

There's nothing wrong with performing this play quite so poetically - in fact, some of the more peculiar moments are really quite sweet and endearing, and fit with the more nostalgic tone - including a lovely moment where Ron turns off his hearing aid and everyone's voices fade away. But some of the more shocking moments jar with the arguments about who gets the first cup of tea and the bingo game, which are both played largely for laughs.

The thing that surprised me most was the play's distinct lack of plot. I can't quite fathom how 'verbatim' the piece is, but the slice-of-life feeling it imparts seems to scream of that - which would explain a more lax story-arc. The moments of plot seem to be pushed along by the darker moments, which I also find hard to understand. Let's put it this way - there were some lovely moments, but I still walked out with my latent Peter-Pan syndrome bubbling up again: I now definitely don't want to grow old.

It's a shame that the show should end up being so depressing - and I'm also unsure as to whether that was meant to be the message here. It's a perfectly well produced, well directed and well performed piece of theatre, but there was no sense of express purpose for putting the piece on. It didn't seem to have anything to say specifically, and on a topic as fraught as growing old I'd have hoped for a more definitive statement or two.

Moon River, at Pleasance TheatreChris Hislop reviews Moon River at the Pleasance Islington.4