The first thing that strikes you about the Corpus Playroom’s latest production is the set. The walls are lined with huge cabinets crammed to bursting and then some more, filled with everything from dictionaries of hymnology to a packet of Frosted Flakes, from glassware to a coat stand. It could give the sense that every detail has been carefully attended to, every object carefully placed, but I’m worried that the effect was more one of haphazard hoarding – and of course, from a narratorial point of view, that was the intention. I wonder, however, whether there’s a difference between the characters being haphazard and the director being haphazard, and I’m not sure how carefully thought-out the set felt.

The opening of the play, sadly, was the shakiest part. I say this because the rest of the performance was far from shaky, Leigh and Bullard shining with confidence in their complexly difficult characters. Alfred Leigh as Daniel was incredible in his interpretation of the autistic Daniel, sitting emotionless and intensely frustrated in his yellow T-shirt at the centre of the cluttered room, wishing Peppy would stop talking and yet humouring her with a wonderful tenderness. Anna Bullard’s Peppy is garrulous, the elder sister who describes to her brother every detail of her day: the woman with a coat, the buses not running, the shops not being open. She tells Daniel to use his listening ears and yet, we feel, she is talking not so he listens but so she can talk: this is what normal people do.

There is a sense throughout the play, neatly captured, of the necessity of upholding an illusion. What is charming and endearing in Daniel in Act One becomes dangerous and suspicious in the eyes of the police in Act Two; what is friendly and zealous in Peppy quickly turns to hysteria and a desire to stave off the silence. They both dance together in this harmony of concealment, avoiding the world and its gaze, but also, it seems, their own.

"the range of emotions which the actors are able to command in this play is certainly impressive"

The double-vision that this play provides is so important. On one side is the audience’s perspective, the events as the innocently fixed ‘truth’ that Daniel writes in his notebook; on the other is the overly suspicious perspective of the outside world as they look in at Daniel and Peppy and their reclusive lives. What we see is an endearing scene, two lonely people curled up on a chair on a rain-clogged evening, reading from Daniel’s diary and celebrating what is gloriously different about them. What the police see is a dangerous man who poses a risk to Ben and to children, and who must be arrested. The moving becomes sinister as the forensics people come in to search the house and cover it in white cloths, constructing the interrogation table out of this whiteness that is terrifyingly eerie, moving to the same piano music as haunts the whole play but this time more minor, with more of an undertone of the sinister and the uncertain.

It is worth pausing here to heap praise on Emily Beck, whose naturalism in playing what is of course a difficult part in the eight-year old boy of Ben was incredible: she was full of energy, bouncing around with a curiosity and complete social innocence so perfect to an eight-year old who cannot understand anything beyond doing what he wants to and spending time with whoever he wants to spend time with – even if this means climbing out of his window at night and scrambling under the fence.

I was pleasantly surprised by the play’s ability to hold its audience’s attention even after two hours without an interval: I was gripped until the very end, enthralled by the characters and their difference which was refreshing and interesting and so complexly layered that I wanted desperately to uncover the reality of their selves beneath all the levels of concealment.

The range of emotions which the actors are able to command in this play is certainly impressive, moving from the tension of the police investigation to the breakdown when Daniel returns home and Peppy takes his place in the chair in the centre of the room, crying out for those who she has lost while Daniel bangs on a metal bowl with a spoon, desperately calling out for the cat. In the final scene there is a new lightness, a brightness as Peppy sews together the bunting and a breath of fresh air as Karen Parry (Charlotte Husnjak) swirls into the scene with her smiles and her picnic and her determination that things will change.

‘The House They Grew Up In’ is a beautiful study of what happens when we are left to ourselves, cut off from the world, through a play which is touched by Daniel’s words as he describes in his jolting and yet perfectly ordered way the world that moves around him, every thought he thinks. This is a play drenched in Odysseus and Titian, cluttered with symbolism which is not always obvious but nonetheless beautiful in its sense of a meaning that lies beneath. There is something we cannot quite put our fingers on – and this ‘almost’ is delivered with such a tenderness and subtlety that we cannot help but sigh when the actors come up for their bows.