A 13-year-old girl is deprived of swimming pool frolics at the birthday party of a pampered contemporary on account of her parents’ lack of lucre. Her trainers — oh horror! —are the hostess’s cast-offs, acquired at a charity shop.

So Blue (Natalie Gavin) takes the plunge in her own way. Down, down she goes to create a submarine adventure in which is re-enacted the tale of Hans Christian Andersen’s The Little Mermaid (and a rather more faithful one in this reimagining than that of the Disney Corporation).

During the 100-minute play our sympathetic young heroine figures not only as the narrator, busy at her writing pad as the gripping action proceeds, but also as doppelgänger to the mermaid (touchingly portrayed by Sarah Twomey) whose story is being told.

Mermaid is the work of writer and director Polly Teale, now entering her third decade as boss of Shared Experience. As a proponent — indeed pioneer — of a powerful, movement-based, text-respecting form of theatre, she has behind her such successes as Mary Shelley and Brontë in which, as here, the source material supplies the launching pad for her own ideas and agenda.

Sinuous movement is in the charge of choreographer Liz Ranken, while Jon Nicholls’s music and sound design supply special magic to a production that has a challenging engagement with the modern world.

While remaining faithful to the original — including Grand Guignol elements such as the removal of the mermaid’s tongue — Teale has much to say about ecology, warmongering and respect (or otherwise) for the monarchy.

As portrayed by Finn Hanlon, the hero prince becomes a dippy, touchy-feely character as much comic as regal. Now where could that idea have come from?

Mermaid
Oxford Playhouse
Until Saturday
Box office: 01865 305305, oxfordplayhouse.com