With one week of rehearsals left before Metamorphosis opens, its leading man, Gisli Orn Gardarsson, has hit a snag - he has to find a way to get from his bed to his chair without turning his back on the audience.
It sounds easy enough, but the challenge lies in the fact that said bed and chair are not on the floor but are nailed to the back wall of the set and hang a vertiginous seven metres above the stage. Gardarsson, co-founder of Iceland's Vesturport theatre company, is no stranger to such challenges, having played Romeo on a trapeze, indulged in aerial gymnastics in Nights at the Circus and directed a Woyzeck that featured bungee ropes and scenes played out in an enormous glass water tank.
But playing Gregor Samsa, the anti-hero of Kafka's novella who wakes one day to discover that he has transformed into a "monstrous insect", is his most physical role yet: "I feel like I've been hit by a train," he says.
As lunch break is called, Gardarsson unstraps his back support and whips off his Boreal climbing shoes to reveal feet covered in plasters. At an athletic, broad-shouldered 6ft 2in with an unruly mop of dark brown hair, the former gymnast towers over David Farr, his co-director and the artistic director of the Lyric Hammersmith, in west London, who cuts a more diminutive and precise figure, dressed in a flowery shirt, jeans and baseball boots. Over omelette and chips in the cafeteria, Farr plays on the contrast: "Gisli's very daring, he works in terms of show and I work more intellectually."
The odd couple met when Gardarsson was starring in Kneehigh's Nights at the Circus at the Lyric in January. Farr, who is "hugely drawn to European outsiders", having successfully adapted Gogol (The UN Inspector) and Dostoevsky (Crime and Punishment in Dalston) had wanted to tackle Kafka for some time. "I had no idea how to do it. I knew that the story required an extra dimension theatrically."
And who better to provide it than the relentlessly innovative and tirelessly physical Vesturport? Gardarsson set up the company with fellow drama students in 2001, renting a space in downtown Reyjavik. "We tend to look at new ways of approaching things", he explains. "Romeo and Juliet [at the Young Vic] was all in the air, Woyzeck [at the Barbican] was in the water and this is on the walls."
Nine months on and the resulting show combines Farr's literary passion with Gardarsson's gravity-defying derring-do, set to a mercurial, melodic score by Nick Cave and Warren Ellis (of the Bad Seeds). Where the music they composed for Woyzeck was based around songs, their Metamorphosis score is centred on the violin, the instrument played by Grete, Gregor's sister, and has a "middle-European feel".
Along with this emotive soundtrack, Borkur Jonsson's split-level set is crucial to the theatrical realisation of the imaginative narrative. The two floors allow the audience to see events unfold both from the family's point of view in the living room as well as from the disorientating perspective of Gregor's altered state upstairs, where his bedroom floor is flipped on to the back wall.
The set is pock-marked with holes that conceal an ingenious climbing frame, helping Gardarsson grip as he crawls up walls and curtains and across the ceiling, as well as other elements of aerial trickery that come into play as Gregor becomes accustomed to his new insect form. In the rehearsal studio, assembled cast and crew on the ground shout up helpful hints as Gardarsson painstakingly plots his route. "It's Kafka's Twister", laughs Kelly Hunter (who is playing Gregor's mother), "Left hand up a bit!"
Kafka's near-perfect novella has drawn myriad interpretations since it was first published in 1915, with critics subjecting Gregor's transformation to Freudian, Absurdist and political interpretations. Kafka himself was wary of imposing too obvious a reading; in a letter to his publisher discussing the book's cover, he wrote, "the insect itself is not to be drawn. It is not even to be seen from a distance." The stage production works on the same principle, dressing the travelling salesman Gregor in a shabby grey suit, shiny with age, that he is "bursting out of through being bored and beaten down by his job".
"The story is so much greater than a guy having turned into a bug. You get that over with in the first sentence of the book," says Gardarsson. "It's about what happens to a human being when they're alienated and numbed by their society," agrees Farr.
While Gregor's despair, isolation and dehumanisation manifest themselves in a particularly alarming way, his family are no less depressed. Earlier on in rehearsal, the cast - who, limbering up in their artfully disarrayed PE kits are by far the sportiest set of actors I've ever seen - have nailed the filmic opening scene in which the family are shown going about their stultifying morning routine. Everything, from the mother's asthmatic wheezing to the spooning of sugar into a coffee cup is timed to fit with the elegiac, rhythmically repetitive soundtrack. A metronome placed prominently on the sideboard emphasises the idea that this is a routine that never misses a beat.
Farr and Gardarsson have inevitably brought a 21st-century perspective to bear on the 90-year-old story. A major addition is a scene in which Gregor dines with his family. The surreal humour of the situation and Frau Samsa's desperate bid for normality - "What we need is a conversation" - owes more than a little to the theatre of the absurd.
"This short story is the father of all of that," agrees Farr. "But I much prefer Kafka to all those absurdists." There are also some political undertones. Fischer, the potential lodger, talks about "clearing the vermin from our society", a historically loaded phrase echoed by Father's assertion that "work will set us free".
"We both find it amazing that Kafka wrote this piece in 1912 and it has this extraordinarily prophetic feel about what society is about to do to itself. It predicts horrors. Without being too obvious, we just wanted to pay tribute to that fact," says Farr, who is, on the whole, dismissive of the "very English obsession with text". Nor is he too worried about living up to past interpretations, including Steven Berkoff's 1969 adaptation in which Roman Polanski, Tim Roth and Mikhail Baryshnikov have all played the lead.
Metamorphosis plays a role in Farr's long-term vision to make the Lyric a theatre for the truly theatrical. "We won't do a conventional straight play in the main house this whole year," he says proudly. "We have probably the youngest and most diverse audience in London. In all honesty they don't look to Peter Hall and Richard Eyre, they look to Robert Lepage and possibly to Complicité, Pina Bausch and Kneehigh."
For those who fear posturing without discernible plot, it is reassuring to learn that the story remains of paramount importance to both directors. "We would never do a physical show without a story - it's just meaningless," says Gardarsson as he chalks up his hands in preparation for the afternoon rehearsal. "You might as well just go to the gym."
Tomorrow until 28 October, Lyric Hammersmith, London W6 (08700 500 511)