Just as Curious Incident (the book) became a must-read on its publication in 2003, Curious Incident (the play) became a must-see after its rave reviews at the National Theatre in 2012. Mrs Chrisparkle and I both read the book and enjoyed it, although we couldn’t recollect much of the story. I’m like that – I can never remember the stories of novels, just the characters. It means I can re-read whodunits dozens of times over and still be surprised at the dénouement; at least I get good value out of a paperback. Late to the party, we finally got round to seeing the stage version last night at the Royal and Derngate, as part of its major 2015 UK and Ireland tour.

When we originally booked, the show was due to run six nights, Monday to Saturday, and we had booked for the first night. A few months ago I received a call from the Box Office saying that the Monday night show had been cancelled as the production team felt they needed longer to get the set in place. Must be some set, I thought. And my word was I right. From the moment you walk into the auditorium to be greeted by Mrs Shears’ German Shepherd with a garden fork plunged through its heart, looking for all the world like some hors d’oeuvres for a Pantomime Giant, it’s hard to imagine a more inventive, contemporary, artistic and indeed scientific set than Bunny Christie’s mind-blowing grid of circuitry and cupboards that constantly comes to life with its own lighting and projections. Even the props that continually emerge from the walls are indivisible from the set as well. Every so often in the first act our hero Christopher would magically produce from inside the walls of the set another handful of toy train tracks and start laying them down on the floor, together with all the attributes of a great train set – stations, passengers, flower beds, signal boxes – even Big Ben and the London Eye. The way they all come together at the end of the first act is simply a joy to behold. A seamless bond between set and props – true stagecraft.

But I’m ahead of myself. I’m sure you know what The Curious Incident of the Dog in the Night-Time is all about, but here’s a quick summary. Fifteen year old Christopher has unspecified behavioural problems most closely related to Asperger Syndrome. This makes it very hard for him to understand the meanings behind what people say as he takes everything very literally. For example, if he was simply told to “stop talking”, he would never know when it would be acceptable for him to start talking again, because that vital information wasn’t provided. He cannot bear to be touched; he cannot cope with large amounts of visual information coming at him from all angles; he has a tendency towards incontinence under stress and won’t use a stranger’s toilet. He’s also an incredibly gifted mathematician and he finds it impossible to tell a lie. His behavioural problems get him into occasional trouble with the police due to his tendency to lash out when they’re asking him questions. But Christopher is a highly moral young chap, and so when he discovers that Mrs Shears’ dog has been murdered, he sets about finding out whodunit, and writing it up in the form of a novel – the novel entitled The Curious Incident of the Dog in the Night-Time in fact. By sleuth and sneakiness he discovers that his mother did not die in hospital of a heart attack, as his father had previously told him, but had in fact run off with Mr Shears and was living in Willesden Green. He can’t bear his father’s lies, so heads off to find his mother. But this is biting off way more than he can chew (which is a phrase Christopher simply wouldn’t understand, as he’s not biting or chewing anything). How far will he get?

Simon Stephens’ adaptation of the novel for the stage rises to the challenge of how to turn a quirky novel into a quirky play. Just as Mark Haddon’s original book had, as its premise, the fact that the book was actually written by Christopher himself, so Mr Stephens’ play also is assumed to be written by Christopher, which gives rise to a few “play within a play” moments, when some of the characters come out of context and deal with its authorship. Nowhere is this more amusingly realised than with the epilogue, which is definitely worth waiting thirty seconds or so in your seat after what appears to be the end of the show. Actually it astounded me by revealing how much geometry and algebra I genuinely remember from school! If all this sounds teasing and tantalising, there are so many moments of visual delight and inventiveness in the entire show that I don’t want to spoil them for you. This is like a multimedia experience – there are so many different ways to enjoy it.

At the heart of this production is a simply superb performance by Joshua Jenkins as Christopher. There aren’t many roles that require you to run the gamut from A-Z as the old saying goes, but this is one. His abrupt mood and tone changes throughout the show, for example going from self-assured detective to bawling infant in a split second, take place with consummate ease. His struggle to cope with his train ride to Willesden is painful to watch as he fights off all the visual and oral stimuli that are hurled at him. One minute he’s sullen and moody, and the next he’s gawping with pleasure at the arrival of an Andrex puppy (as indeed are the entire audience). You never feel like he’s an actor playing a role; you really feel he is Christopher, coping with the world in the best way he can. Totally credible throughout; an amazing performance.

There’s a moving and sensitive performance by Stuart Laing as Ed, his father, supportive of his son but driven to distraction by him too; his attempts at discipline are usually not worth the fight and he’s clearly reticent about making bad situations worse. There are a few very tender moments when he just watches Christopher in awed silence, not quite believing that he could have a son this remarkable. As a balance, there’s a lovely spirited performance by Gina Isaac as Judy, Christopher’s mother, something of what the Dowager Mrs Chrisparkle would have called “a good-time girl”, but also deeply caring for her son, and the semi-reconciliation that occurs between the two parents is heart-warming to observe. Geraldine Alexander gives a lovely performance as Siobhan, Christopher’s school teacher and mentor, with the perfect mixture of friendliness and professionalism that you would have to maintain in order to do that job correctly.

The rest of the cast form an ensemble around the character of Christopher, and give great support; to pick out a few, I really liked Clare Perkins as the Headmistress who always repeats the sentences that Siobhan has previously narrated – a very funny running joke; Roberta Kerr as the elderly neighbour Mrs Alexander who really wants to befriend Christopher except that he won’t let her in; John McAndrew as the “too old” Reverend Peters; and Lucas Hare as the wretched Roger Shears who hopes Judy ditches her rediscovered son as quickly as possible. The ensemble work is powerful and thought-provoking; I loved the balletic, physical theatre-type moves between the actors and Christopher as he floats and bounces off them in various dream sequences; members of the ensemble even take on the roles of doors, latches, windows, and so on in order to accentuate the physical achievement of Christopher successfully negotiating an ordinary day. There’s a great moment when Christopher is lifted on his side so that he can walk along the sides of the walls – not seen anything like that since Bert did his gravity-defying dancing in Mary Poppins. The whole thing is magic to watch.

Despite the large numbers of children in the audience – this is now a set text in schools – this is far from being a “children’s play”. There’s an appropriate amount of bad language in it, considering the level of stress that some of the characters face, and it deals with some difficult subjects like broken relationships, lies, and challenging behaviour. But it’s extremely funny and creates a fantastic dramatic environment where we see the world through the eyes of one unique individual. A memorable theatrical experience that ought to be compulsory viewing for everyone! The tour continues throughout the UK and Ireland till November.