Edinburgh Festival Fringe: Tank, Pleasance Dome, review: 'Fascinating gem of a show'

In the Sixties, American scientist John C Lilly conducted a project attempting to teach dolphins to speak English. It was funded by Nasa: they wanted to be prepared for communicating with aliens. One young researcher, Margaret Howe Lovatt, got so involved with one dolphin, Peter, that in 1965 she spent 10 weeks living in isolation in a tank with him, trialling a mother-child model of language teaching. But Peter became both aggressive and, er, problematically aroused; Margaret ended up masturbating him. The experiments were recorded; some parts have been transcribed.

Sixties dolphin sex: a wacky fringe premise, right? The above is all actually true. Part of the transcripts are recreated verbatim in Tank, the arresting, clever show from Breach Theatre, a young company whose play The Beanfield caused a buzz at last year’s fringe. One of the foursome plays the dolphin; microphone effects, and the more lo-fi method of gargling water, help recreate the sound of Peter learning to speak.

Except does he really learn to speak English? Despite Margaret’s pleading, Peter never gets very far. Which makes the lengths that the researchers go to in trying to impose their language on these creatures even more troubling.

Tapes of lessons are not much to go on, and Breach’s play acknowledges from the start that they are fleshing out this story – and that, even in verbatim theatre, there are many ways to do so. The actors unfold events as if describing the shots of a movie, but squabble over how to realise it. This starts lightly – does Margaret drive a second-hand banger or flash pair of wheels, does she wear heels, flats or boots? – but the questioning tactic comes into its own further down the line. Just how fair are these experiments on the animals, and on Margaret? And what exactly is the nature of the narrative: could it even become a love story?

Maybe it was the conditions of the unnatural experiment that drove Peter to be aggressive, even biting Margaret, or maybe he was just playing; maybe he desired Margaret, or maybe it was pure mechanical, animal needs that caused him to get erections. Maybe there really was love between them. But if it was love, it was also deeply destructive. It’s no wonder people get hung up on the woman-wanks-dolphin bit, but Breach provide many sides to the story – the warped romance, the cooler scientific view, and a powerful sense of the damage done by human hubris.

The actors' open acknowledging of all this is slickly done, and deepens the piece. With two men and two women in the cast, Tank also archly suggests that gender colours the way we retell such stories; the urge to fetishise this young woman and her experience must be repeatedly shut down by the female actors.

Tank is not perfect: it more comes to a soggy end than finds a final splash. But this comically knowing yet deeply humane exploration of compelling source material makes for fascinating gem of a show.