People who saw the first movie version will be surprised by the changes, which go far beyond the original's unexpected plot twist. The Nobel Prize winner's screenplay, claims Branagh, "took an entirely different tack. It's ingenious in its dark humor and far away from the flamboyance of [the 1972 picture]. "This film is leaner and meaner."

Continues Branagh, "As an actor, Harold as David Baron [the writer's stage name] was terrific and played in many, many thrillers. He admires them hugely, but it's not his strong point [as a writer]. So, to inherit the theatrical mechanics of the central theme — two men [author Andrew Wyke and actor Milo Tindle] playing a deadly game and fighting over a woman whom we never see — suited him. [The woman is Wyke's wife and the younger man's lover.] Harold kept the center and turned everything else around."

Branagh read the screenplay "from start to finish [in one sitting]. I gave it to my wife [Lindsay Brunnock], and she couldn't put it down either. Pinter's last 'act' has a homoerotic possibility. Is Andrew attracted to Milo? Or is it his ultimate sick provocation?

"Harold said, 'I'm not good with plot. I'm not interested in plot.' For him, of course, it's all about character and atmosphere — which, I think, is quite a good marriage."

Onstage, both in the West End and on Broadway, where it won the 1971 Best Play Tony Award, "Sleuth" starred Anthony Quayle and Keith Baxter. Shaffer wrote the screenplay for the 1972 movie, directed by Joseph L. Mankiewicz, and for which Laurence Olivier and Michael Caine both received Best Actor Oscar nominations. This time around, Caine takes over the Olivier role and, as he did in the recent remake of "Alfie," Jude Law succeeds Caine.

Actors, all of whom were not seen, were listed in the credits of the play and the prior film. Was the extra cast considered for this version, which may (or may not) feature two characters? "It was," states Branagh, "but I suppose to not do so might be another way to distinguish ourselves from the original. We tried to stay away from that. The Mankiewicz film is utterly delicious and many people will know its twist. We tested [the new film] in front of a young audience, who had never seen the original. They gasped [at the twist].

"It's quite hard, you know, to come up with names of actors that don't sound a tiny bit phony." I mention that in the first film, Wyke's wife was shown in a framed photograph (actually of Joanne Woodward) and was billed as Eve Channing. "Exactly!" says Branagh. "Fair enough if you're Mankiewicz [to combine the names of two "All About Eve" characters], but we decided to avoid that pitfall."

Might the woman seen on a screen in Wyke's home be his wife, Maggie? "It was the actress whom we cast as Maggie," admits Branagh, "and indeed we shot a number of scenes with her. But we decided, during the course of filming that the more we showed of Maggie — even fleetingly — the less powerful she became. When we don't see her, she becomes enormously powerful. You're the first one, Michael, to actually ask if it's the wife. In fact, it is, but I've ducked the issue."

In this version, Wyke is very much involved with gadgets. He uses an ever-present remote control to remove walls, erect screens, operate an elevator, etc. Originally, Wyke was obsessed with games and puzzles, because the inspiration for the character was a composer-lyricist who's fascinated by games. The working title of the play was "Who's Afraid of Stephen Sondheim?"

Branagh's New York stage credits include directing his play "Public Enemy" at the Irish Arts Centre in 1994, and directing the Broadway production of "The Play What I Wrote" in 2003. It was recently announced that, for the Donmar Warehouse's 2008-09 season at Britain's Wyndham Theatre, Branagh will play the title role in Tom Stoppard's adaptation of "Ivanov", and direct Jude Law as Hamlet.

I inquire about an early scene in "Sleuth," where the two men share a drink, but only their midriffs are seen. Explains Branagh, "It was part of an attempt to unsettle the audience visually and put them in Milo's position. It begins with an overhead shot of Michael [Caine] introducing himself. Then they get into this ridiculous conversation about which of their automobiles is bigger. I try to discombobulate the audience a bit and not fully reveal the characters' faces until about 12 minutes in, when Michael sits down into a close-up and says, 'I understand you're sleeping with my wife' — although he puts it rather bluntly. It was an attempt to make it cinematic and not theatrical."

Relates Branagh, "I remember an example of Harold's love of ambiguity. When I asked in rehearsals what Maggie is saying on the other end of the phone in the two calls Milo receives in the last 10 minutes, he replied, 'What do you mean?' I said, 'What is Maggie saying?' Harold said, 'The phone rings, yes, and he appears to be talking to someone, but we don't know what's being said — or even if it's Maggie.'"