You have to admire anyone who sets out to make a new musical. The sheer array of skills required boggles the mind. Arguably the most essential of these is not the writing of the music, but the show's book on which everything is built. This one, however, written by composer Eamonn O'Dwyer and Rob Gilbert, is out of balance with too little work on character and too much reliance on mood.

The setting is a shadowy house populated by widow Anna (Gillian Kirkpatrick) and her two daughters. The three live in a state of mutual resentment, not least because Anna blames her eldest daughter Laura, for the death of her children's father David, an artisan maker of mirrors who died in accident. Or was it?

If the creators of this show had hoped to keep their audience in a state of suspense about the circumstances of David's death, they failed.

Once you twig the identity of one of two male lodgers in the house, the dramatic revelation towards the second of two slow acts is actually no revelation at all. So, in storytelling terms, Ryan McBride's intricate production is a longish wait for the inevitable. But the real difficulty here is that even the emerging love story between the new lodger Nathan and Laura (Grace Rowe) doesn't release O'Dwyer's score from its relentlessly downbeat feel.

As the current revival of Gypsy proves, music can be ironically upbeat while staying true to a musical's dark themes. It's variation I'm arguing for, not optimism.

Here, there is belated emotional uplift when Nathan - played by the talented Jamie Muscato who was last seen in the magnificent American musical Dog Fight at Southwark Playhouse - sings his heart out after he and Laura finally fall for each other. And if O'Dwyer broadens the emotional range of his intentionally discordant music, his next show could be well worth catching. But it says a lot about this one that the relief felt when everyone is put out of their misery is not confined to the characters.