Look who's talking

Jeremy Northam is hanging about outside the Tate Modern, where he has just been to see the new Edward Hopper exhibition. How nice it must be to be an actor, able to just pop into a gallery on a sunny afternoon.

Except Northam is here on business: specifically, research. He's appearing in a new production of Harold Pinter's 1971 play Old Times and the director, Roger Michell, has hit on the idea of checking out Hopper, whose tense, empty paintings place a similar, undefinable emphasis on silence as a Pinter play.

Actually, Northam doesn't like Hopper very much: 'Too chilly. Although there's certainly something imminent about the paintings. Someone said to me they reminded him of a set before the actors arrived.'

Northam is wearing sunglasses, which means I can't accurately test my theory that he is unrecognisable in the flesh.

He's been in a slew of classy films, most of which required him to play an Englishman in breeches - Emma, Merchant Ivory's adaptation of Henry James's The Golden Bowl, Carrington, and Robert Altman's Gosford Park. Yet he remains the type of actor people have heard of but cannot place.

Northam talks of the dangers of being typecast if you look a certain way (ie a bit posh) and refers, with more hurt than bitterness, to a couple of film roles he wanted (he won't name them) but didn't get.

Anyway, Pinter. Northam plays Deeley, husband of Kate, whose best friend Anna comes to visit for the first time in 20 years. But the past becomes a battle site, with Deeley and Anna fighting to exert some sort of emotional ownership over Kate.

'It's a tug of war,' says Northam. 'It's a play about the ambiguity of memory. Anna says at one point: "There are things I remember which may never have happened but as I recall them, so they take place" - which is something that's demonstrated again and again throughout the play.'

I suggest the abstract world of Pinter must be a particularly challenging proposition for an actor more used to the concrete reality of film. He disagrees. 'Actually, I find cinema very abstract. The storyline is out of order. You constantly do things from different angles. However odd a play might be, at least it takes place in real time, where everything is there.'

Except, with Pinter, quite often things are not there. Character, motivation, meaning: you can get into a terrible muddle trying to divine what a Pinter play means. Northam agrees it's foolish to spend too much time 'talking the play to death', although one gets the impression this is precisely what he could do. Northam is an intense, considered talker, certainly not one for flippant, casual chat.