A curious accident of emphasis has occurred in the transfer of this brilliant National Theatre production from the Cottesloe to the middle of Shaftesbury Avenue: Luke Treadaway's autistic mathematical genius Christopher Boone has become Hamlet, alienated in a harsh world he views with a piercing and unforgiving clarity.

It's as though Simon Stephens' adaptation of Mark Haddon's cult novel has been turned on its side and shown in relief. I don't think this necessarily improves or enhances Marianne Elliott's production - it's an inevitable consequence of moving within a proscenium arch - but it makes it more of a "play" and less of an experience.

Boone's Elsinore is Bunny Christie's black graph paper design illuminated with deft wit and beauty by Paule Constable's lighting. Treadaway and the nine supporting actors - led by Niamh Cusack's sympathetic teacher, Siobhan, who translates Christopher's book into a school play - are drilled into a flexible, expressive ensemble by Frantic Assembly duo Scott Graham and Steven Hoggett.

Rather like War Horse, it's the best sort of experimental luxury theatre, ideal for West End consumption. Whereas the book proceeds at an even tone - the point is that Christopher sees and describes everything equally - certain passages are here highlighted for dramatic effect: the escape from Swindon by train; the descent to the tube on a huge escalator that seems part practical, part projection; the desperate search for Toby the rat on the electrified railway.

And of course we have that big soppy "ah" moment, a real live adorable puppy, Sandy the embryonic golden retriever. Otherwise, the show is admirably harsh and concentrated on Christopher's project of solving the murder crime (Mrs Shears' dog Wellington is the hairy carcase with a garden fork in its gut) and finding his mother in Willesden (with her ungracious lover).

Treadaway is truly remarkable as Christopher, not least in the way he arrogantly turns tables on "ordinary" people and manages to convey the nature of his "disability" as a distinct advantage, just as Hamlet's soliloquies are clear evidence of special powers. And the staging of the book's appendix, in which he describes the two-minute proof to the A-level problem is just dazzling.

Three newcomers to the cast, all excellent, are Seán Gleeson as Christopher's perplexed dad, Holly Aird as his guiltily sulphurous mum and Tilly Tremayne as Mrs Alexander. Worth noting, too, that "at some performances," Christopher is played by new Bristol Old Vic Theatre School graduate Johnny Gibbon; let's hope that, in the spirit of The Goodies, he's a funky one.