Poppy Shakespeare by Clare Allan

We are immersed in the claustrophobic world of the Dorothy Fish Hospital in north London, where day patients - or "dribblers" - including our narrator, "N", talk, smoke, and plot to ensure that they are never discharged. But this bubble is popped by the arrival of Poppy Shakespeare, a young woman convinced that she is not ill. When N is assigned to be Poppy's guide, a halting friendship develops, centred on Poppy's determination to leave.

All is delivered via N's unstable, ungrammatical English; it's a difficult voice at first, but Allan finds a lopsided, compelling poetry in it. At the hospital "... the madder you was, the higher you gone," and on the top floor "you'd see right round the world and back in through the windows behind you."

Often this deadpan account is aimed at cartoonish supporting characters - with names such as Middle Class Michael and Slasher Sue - but the novel's comic brilliance is in its satire of a healthcare bureaucracy that, in Allan's hands, erects a hall of mirrors around the patients. In one passage, N faces her monthly assessment. "Do you find it hard to make decisions?", she is asked. "I seen the trap straight off: if I said I strongly agreed they could say I was lying on account of I just made one, and if I said I disagreed they could say there were nothing the matter. So in the end I gone with neither agree nor disagree."

Allan recognises though, that N's determination to stay at the Dorothy Fish for ever is also this novel's greatest sadness. In the latter stages narrative pace - allowed to drift for too long across the minutiae of hospital life - quickens, and we get finely drawn dialogues in which Poppy and N plot the latter's escape. N proves crushingly inarticulate concerning her own institutionalisation and, crucially, we discover the essential sadness of her life via brief details: when Poppy sees a picture of N as a child, she hugs her and says: "I'm so sorry!" It's typical of Allan's skilful, and moving, presentation of the emotional heart of this story as though in passing, buried amid comic furore.

Here is a fractured, elliptical narration, then, made to suggest that individual mental illness is a phenomenon too slippery ever to understand fully. But it's Allan's refusal to preach that truth, her skilful implantation of it into fiction, that makes this novel a success.