That this should be the National Theatre’s first production of All’s Well That Ends Well is at once surprising and entirely understandable. A problem play in the truest sense, on the page this late ‘comedy’ combines a weighty and implausible scenario with passages of unexpectedly inelegant dialogue. Pick through the red herrings however, and you will find some of Shakespeare’s most curious and contemporary characters, and a play whose charms are all the sweeter for being hard-won.

Following the fortunes of the lowly-born Helena, the play charts her attempts to win the hand (and later the heart) of Bertram, son of the Countess of Rossillion. His disgust at being forcibly married to a commoner provokes Bertram to issue Helena a series of apparently impossible tasks before he will agree to the alliance. Add a supporting cast extending from the King of France to a variety of eccentric family retainers, throw in a quest to distant lands, and you have all the ingredients of a classic fairy tale.

It is this insight that proves the key with which director Marianne Elliott and designer Rae Smith unlock this awkward play. Rather than underplay the plot’s inconsistencies of tone and extremity of action, they rather makes a virtue of them, trading realism for a stylised grotesque that juxtaposes the gothic tableaux of Tim Burton with the candy-coloured excesses of a 1950’s musical. The effect is magical – a silhouetted castle on a craggy ridge gives way to a bright Florentine square, just as the monochrome landscape of Dorothy’s Kansas becomes the colourful scenery of Oz.

The cast is universally strong, led by Michelle Terry as Helena, whose efficient assurance contrasts nicely with the weakly patrician Bertram (George Rainsford), with his smooth-cheeked posturings of manliness.

In the hands of Elliott and the National Theatre, “All’s well that ends well” ultimately becomes a question rather than an all-too convenient affirmation, and one delivered with all the elegance of the Grimmest of fairy tales.

Until September 30. Box office: 020 7452 300 (www.nationaltheatre.org.uk)