It was a sign of Dickens's maturity that he went along with it. It's very modern in that Eugene throws up questions that remain unanswered. When you think of Eugene's motives, there are times when he is very close to damnation It's not crucial that we make him likeable. But even in this life-or-death battle, Eugene finds it hard to lose his characteristic sense of ironic non-commitment and moral dubiety.It was Eugene's duality that first drew McGann towards him "The very ambiguity of the character makes it a plum. But give me something to be energetic about and, by God, I'll show him energy."That something soon arrives in the shape of Eugene's cataclysmic struggle with the self-made school-teacher, Bradley Headstone (David Morrissey), for the love of the pure boatman's daughter, Lizzie Hexam (Keeley Hawes). A "resting" barrister, he has turned apathy into an artform, complaining: "How could I possibly undertake matrimony, I am so easily bored, so constantly, so totally?" He sighs that his ambitious father "continually berates me for my lack of energy. He's the sort of man who relishes lazily sniffing an unlit cigar before putting it in his top pocket.

But I liked him for the poise he had and the time he gave himself, as if he was saying 'It's going to happen anyway, so you don't have to give it away cheap'."Eugene fits snugly into this canon of enigmatic, disengaged characters. The producer of Doctor Who said I had an outsiderish quality. It's not cosy."When I was a kid, I loved Dirk Bogarde - why is that? You wouldn't say on the face of it that he would be a child's favourite actor. What is more interesting is that they're all heroes in their respective stories, yet for audiences they're not the easiest of people You don't give your allegiance to them easily They're strange and awkward.

It is a copy of the great director Michael Powell's memoirs which has been dedicated by his widow, the film editor Thelma Schoonmaker, to McGann, "who knows not to give it all away". "I couldn't have been paid a better compliment," he smiles. Sporting Eugene's dashing whiskers, dark tartan trousers and opera cape, McGann points up the similarity between this character and other celebrated creations of his: Dr Who, I in Withnail and I, and Private Percy Toplis, aka The Monocled Mutineer "They're all marginals. McGann has made a speciality out of such insouciant outsiders. Lying casually on the bed - not unlike Eugene - in his caravan between scenes on Our Mutual Friend, McGann directs me to a book on the sideboard. The camera then moves round to show a man draped languidly across the cushions, well away from the crowds at a society wedding It is an image of yawning, nonchalant detachment.