Metamorphosis, Lyric Hammersmith

While Kafka specifically declined to indicate exactly what kind of creature Gregor Samsa becomes in his horrific overnight transformation, translators of the novella have gone for a variety of options: bug, beetle, cockroach or vermin.

This production, a joint enterprise between the Lyric and the Icelandic company Vesturport, was first seen here in 2006, returned in 2008 and has toured the world, from South Korea to New York, Australia to Hong Kong. It is not difficult to see why it continues to grip audiences. To begin with, the set (by Börkur Jónsson) immediately introduces the twin notions of dull conformity and terrifying dislocation: Gregor wakes in a topsy-turvy room in which the floor has become a wall and a wall the ceiling. while below his parents and sister inhabit an unremarkable dining room and begin familiar morning rituals.

Garðarsson and Farr address graphically the question raised by Kafka - what exactly it means to be human

Garðarsson, once a member of the Icelandic gymnastics team, is mesmerising, bending his tall frame into ugly shapes, clambering over vertical surfaces and yet somehow maintaining both a naturalness of movement and his humanity. As his diminutive sister Greta, Nína Dögg Filippusdóttir moves from sympathy to disgust to willingness to get rid of the troublesome thing her brother has become in a manner which is disturbingly easy to understand.

There are comic moments as Gregor’s parents, played by Kelly Hunter and Ingvar E. Sigurðsson, attempt to hide their awkward secret, specifically from the would-be lodger Herr Fischer (an amusingly preening Jonathan McGuinness). The family’s financial desperation, having lost Gregor’s income, has come sharply into focus since the production’s first outing before the events of 2008.

The style of costumes and furnishings is non-specific 20th-century, but certainly later than the 1915 publication date of the original. This allows for creepy premonitions of Nazism in the desire to get rid of one who is different from the accepted norm. Garðarsson and David Farr (who are both responsible for the adaptation and direction) address graphically the question raised by Kafka - what exactly it means to be human. Music is important in the story in indicating Greta’s sensibility and her closeness to her brother as, to begin with, she plays her violin and Gregor, who had intended to help her gain a conservatoire place, listens upstairs in painful frustration. Music – by Nick Cave and Warren Ellis - is important in the production too, providing a lyrical but brilliantly disconcerting dreaminess.

In the final moments, as Gregor dies (in a stylised, acrobatic manner) and his family sets off on a new, sunny life, Farr, Garðarsson and Cave conjure a horribly seductive mixture of emotions: relief, pity and even, perhaps, a worrying sense of complicity.

• Metamorphosis at the Lyric Hammersmith until 9 February