Introduced, she offers no hand and flashes an almost aggressive look, challenging you to not come in. She helps herself to a drink and mutters: "It's like the dentist's. She has just concluded another interview which has overrun by 20 minutes. I am next.
Having turned her back, temporarily, on Shakespeare and sex, Miss Rigg, ex-Viola, ex-Emma Peel, is now embarked on a third career, as a film star. Her first manjor effort comes up for judgement next week. It is called Assassination Bureau and she plays an educated, beautiful woman who breaks into the exclusive world of male journalism in 1906.
She seems to find film-making rewarding. At the moment she is making another, On Her Majesty's Secret Service, the new James Bond epic.
"I play a girl who has everything. She's extremely rich and devil-may-care. I know that sounds a bit dated. But she meets James Bond and she's not a push-over. That's what attracted me."
"She's not a victim. She selects him, on terms of sexual equality. That's what I like about her."
Miss Rigg's own philosophy in life is never to be a victim. She has consciously avoided going to film in Hollywood. "The way you are manipulated in Hollywood means you can't fight. They don't recognize the individual. For me, that's the most important thing."
So far, she has not been offered the film role to match her potential. "The roles so far have been one-dimensional. I'd like a dramatic role in a film. But whether I get that depends on director, script and the funny little accountants who give money for films and who are men of limited vision.
"If one is successful in a role they are not going to hazard their money on another kind of role that is completely diverse."
"That's what one has to struggle against. There is no such thing as success. It is all extremely ironic. You are always fighting against not being allowed to progress.
"I have broken away in life once. I was viewed as a classical actress with the Royal Shakespeare Company and firmly decided I would not sign a contract for another season. I thought I would hazard everything. Then I got a job on TV and I was categorised again.
"What do you do? It's rather sad?"
Miss Rigg leans back in the chairand flashes Emma Peel's winning smile. She does look stunning, and the brown eyes look at you with a slightly alarming directness. She talks in the nicely modulated tones of a former member of the Royal Shakespeare Company.
Will she go back to the stage? "I've no immediate plans for anything. I'm not interested in what I'll do next. I'm committed on the Bond film and I can't do more than one thing at a time. I'm giving it my total attention and am not interested in what might be lined up afterwards.
"I'd like to go back to the theatre. I've always dreaded Lady Macbeth but I think I'd like to do it now, and I'd like to play Portia."
Financial rewards from films?
"Because of the world in which we live, all I make is siphoned off by various wise gentlemen. I'm back to where one started as a child, holding one's hand out for pocket money.
"I don't have grandiose tastes. I'm fairly simple. You have obligations when you are earning money and commitments to other people. That's the greatest happiness about it, and I don't mean to sound schmaltzy.
"I don't go out and buy lots of things. When I used to go home on the bus every night from the Aldwych I'd window-shop, thinking of what I could afford. Now you have the money you still can't go mad.
"The tax situation for my profession is absolute hell. It's frightening. For one good year you can be landed with enormous tax the following year. Who wants to be bankrupt?"
She said she hated working in a film studio. "It represents the total artificiality of the film world. I much prefer working on location. I feel realised then.
"In the studio I'm not sure which is more important: how good you look or how good you are. On location I think you come closer to both.
"I do miss an audience. Working in the theatre is like this Pavlov thing. They ring a bell and you go up on the stage. There's no bell in the studio. You get up at a god-awful hour in the morning and it's all much harder.
"When you have an audience there is expectancy and demand and you respond. In a studio there are disinterested parties around.
"I defy anybody to be turned on at 8:30 in the morning after you've been slapped around from 6:45 with make-up and your hair in rollers. I think it's a personal outrage and always shall do. I'd like to have the power to dictate that I should work like they do on the Continent. They don't start filming until 12 o'clock. That figures to me."
We talk about The Avengers. She has gone on record as saying her acting in it was "a load of old codswallop." She said she had wondered how much her personal ego would suffer when she gave up Emma Peel.
"TV is so immediate. Within a week of my appearing in the first installment I was recognised by 90 per cent of the public. A taxi driver said to me, 'Haven't I seen you somewhere?'"
It seems time to go. She asks eagerly as she gets up from her chair, "Is that it, then?" She shakes hands when you leave.