Seat of learning: A wine bar in London's theatreland plays host to monthly meetings of a very exclusive club. Emma Cook pitted her wits against them

It's got to be one of the most harrowing ways of earning 15 minutes of fame - sitting in Mastermind's black chair and baring your intellect to the scrutiny of the BBC's coolest question-master, Magnus Magnusson.

'There's no obvious reason why you go on,' says Paul Henderson, who reached semi-final stage in 1987 with Russian Music 1860-1960 and is a member of the Independent's crossword setting team, 'but it does allow you to learn more, show off and be an expert.' He is a member of the Mastermind Club, which has over 400 members - all of them ex-contestants. 'I treasure the memory,' he says. 'People think it must be terrible sitting there, but it's not. There's no time to be emotional about it.'

He is one of about a dozen club members who meet up monthly in a wine bar on Shaftesbury Avenue to keep the memory alive. Their conversation is animated, every detail of their experience discussed.

'It's like amateur dramatics,' says club president Tony Dart. 'You rehearse for it, then it's all over in a flash. It's an enormous anti-climax afterwards.' Tony appeared in 1981, specialising in the novels of C P Snow: 'I still haven't been able to pick up any of his books since'.

Mastermind was the 1972 brainchild of BBC producer Bill Wright. The idea came in a dream: black chair, ominous music and all. He woke up his wife to relate the experience and the rest is, as they say, history.

Few modifications have been made since. The title music, aptly called 'Approaching Menace,' by Neil Richardson, survives unchanged. Only the chair has been altered. The swivel base was removed after nervous entrants used to accidentally spin round in it. The hard, inquisitorial style, so unique to Mastermind, was based on Wright's memory of Gestapo interrogations in Germany.

Perhaps it's no coincidence, then, that one club member compared appearing on Mastermind to 'getting through the war and surviving'. Like war veterans, they like to discuss tactics and manoeuvres. 'Never fall into the 'pass' syndrome,' advises John Flashman, who specialised in John Constable. According to members, this is the easiest way to weaken. 'If you say it once, you'll find yourself passing on every question.'

All of them would gladly return. 'We all know we're capable of winning it,' says Henderson; 'I'd love to go through it again.' Yet winning a spell in the black chair is almost as hard as winning the final. There are over 2,000 applicants a year, of whom 300 are considered. A Mastermind producer will travel the country for three months to audition candidates, testing general knowledge and assessing their television potential.

What sort of super-human intelligence do the chosen few need? 'It's speed of recall more than anything else,' says Dart. 'In theory we know everything we've ever learned. It's just accessing it.' They all agree that their responses to Magnus's questions are often unconscious, rarely thought out. 'It taps into something entirely different,' explains Flashman. 'After each answer I thought 'How did I know that?'.'

They each describe the two minutes of interaction with Magnus reverentially. 'I can watch the programme and still remember that corridor of light between me and him,' says Henderson. 'The intensity is almost religious - you really are that close to him.' Flashman agrees: 'It's just between you and Magnus. When you're being questioned you don't care about the outside world at all'.

The Mastermind final is on BBC1, Sunday 21 August at 10.05pm

(Photographs omitted)