Lesser mortals might recognise his sniffly nose and slightly raspy voice as symptoms of feeling a bit under the weather but you can hardly blame Cumberbatch for viewing a mere cold in epic terms.
Tonight he opens in Danny Boyle’s hugely anticipated theatre production of Frankenstein, sharing with Jonny Lee Miller the roles of Mary Shelley’s scientist Victor and the ‘monster’ he creates from spare body parts.
‘It’s a hard ask on both fronts,’ grins Cumberbatch, who in baggy tracksuit and trainers looks a galaxy away from the dashing, nerdy sleuth TV viewers know him as from the BBC’s new series of Sherlock Holmes.
‘You come off stage with a cut on your lip and a joint out of place, your wrists are bruised and you’ve just shed five pounds of body weight.’
The original idea for casting two actors who would alternate as creator and created was Boyle’s.
He started thinking about adapting Frankenstein with the writer Nick Dear almost 20 years ago before an Oscar-winning film career distracted him.
‘The way the creature starts copying his creator is one of the key narrative drives,’ Boyle says excitedly, his enthusiasm for the show apparently undimmed by weeks of hard-core rehearsal.
‘He is born good and learns evil. They are distorting mirrors of each other, photocopies.’
Today, Shelley’s 1818 masterpiece, which famously began life as part of a ghost story-telling competition with her husband and Lord Byron on the shores of Lake Geneva, has become indelibly associated with its Hammer horror incarnations depicting mad scientists and evil monsters on the loose.
Yet both Boyle and Cumberbatch are keen to release the novel from its Gothic melodrama moorings and emphasise the social and personal context in which it was written.
‘You had this massive burst of the Industrial Revolution, which was really about electricity and the magic of light and life that gave,’ says Cumberbatch, who sees Victor as being in a long line of übermenschen who think they can change the world but destroy themselves in the process.
‘Victor is also motivated by the death of his mother, who died caring for his cousin; he’s also got a very complex relationship with his fiancée Elizabeth, so for him there’s a massive motivation to conquer death in this world of darkness.
‘He see himself as a hero but, by the end, it’s become a suicidal pact.’
‘Mary Shelley had been constantly pregnant in the lead-up to writing the novel and had already lost a child,’ adds Boyle, whose own children were very young when he first started thinking about Frankenstein, and who admits the show has become very personal for him.
‘And here she is writing a novel about this self-obsessed egoist creating life in a way that excludes women.
‘That’s why I wanted to do it on stage rather than on film, because movies have done so much to distort the story. We wanted to give the creature his voice back.’
Cumberbatch, an actor of rare emotional intelligence on stage, and cerebral and charming in the flesh, is quick to bat away any audience preconceptions about how he and Miller might approach both roles.
‘I hate this distinction of me being some f***ing academic who has just managed to escape the allure of some postgraduate course, and Miller as this mad f***ing wild child with dyed hair from Trainspotting,’ he spits.
‘We have different working methods but ever so slightly – we block on the same lines. We’ve got the same sense of humour and think much the same about what’s good and bad.’
Boyle, for his part, draws no distinction at all.
‘I just wanted two stonking actors with the arrogance to feel no fear,’ he laughs.
Did he feel any fear about returning to the stage after so long working in film?
‘I did keep forgetting I wasn’t filming,’ he says.
‘I’d walk up to actors during particularly intense moments in rehearsal as though I had a camera and was trying to get in close. I soon put a stop to that.’
Both Boyle and Cumberbatch see Shelley’s multifaceted novel as being about responsibility.
‘What really goes wrong in this experiment is that Victor doesn’t care for what he’s created,’ points out Cumberbatch.
‘I suppose you could say it’s ultimately a novel about bad parenting.’