Theatre review: Responsible Other, Hampstead Downstairs, London

Daisy (superb Alice Sykes) is nearly sixteen and might have expected to be tumbling through the teenage rites of passage with her peers – from studying for mock-GCSEs to trying to sneak into clubs with a fake ID.

Instead, she languishes at home in her novelty onesies, disaffectedly flipping between laptop and trash TV. Having lost her mother to cancer only eighteen months previously, Daisy has herself been been diagnosed with the auto-immune disease Lupus which can cause life-threatening organ damage.

Peter, her father (spot-on Andrew Frame) is a good man mortgaged to the hilt and struggling to hold everything together in the face of this second major crisis in quick succession. He and Daisy are close but still in their separate bubbles of grieving and, with this new additional stress, they can only communicate through the warfare of mutual exasperation. 

It drives him mad that his daughter forgets to take her pills and neglects to keep up with her homework chart. Hurt and angry in her belief that he is treating her as set of problems rather than a person, Sykes's Daisy brilliantly suggests the accumulating loneliness behind by the rebellious campaign of pouting adolescent truculence and stroppy one-liners. The crunch comes when Peter needs someone to take her to St Thomas's in London for her weekly chemotherapy sessions and has to turn to a reclusive maternal aunt, played by Tricia Kelly, who's transfixing as a chronically buttoned-up woman for whom it's a battle to get through the front door let alone to the South Bank.

You might be thinking that this scenario is bit top-heavy with troubles and would make for grim evening. But Melanie Spencer's exceedingly attractive and accomplished debut play Responsible Other is full of lively wit and sharp observation, as her beautifully acted production brings out. The scenes with Candassaie Liburd as Daisy's school-chum Alice, who visits with work-sheets and gossip about Slutty Ashley and “drinking Malibu in Vicky's bedroom” and group realignments, are little comic masterpieces about the proprietary nature of teenage female friendship. What's touching is that the well-meaning Alice is blunderingly far from the epitome of cool (she's hoping to “catch bulimia...before One Direction at O2”) and that, though sceptical, Daisy can't resist being envious. 

The potentially sentimental growing rapport with the aunt is likewise handled with humour and oblique poignancy, starting off with tentative train-journey exchanges about Heat Magazine articles on Lady Gaga and lactose-intolerance where, though the pair barely speak the same language, it's an improvement on silence. Warmly recommended.

To 20 July; 020 7722 9301