Sir Arthur Conan Doyle stares out reassuringly from his portrait above the fireplace. The tilt of his head is slightly defiant, no doubt the product of enduring years of ridicule in his crusade in defence of spiritualism - the idea that you can communicate with the "other side". It was a trend so fashionable between the mid-19th century and the end of the First World War that even Queen Victoria had a go at it.
Sir Arthur, whose comical handlebar moustache makes me smile, looks down upon 12 people in the Conan Doyle Room at the British Spiritualist Association headquarters in Belgrave Square, central London.
They are an odd bunch, fidgeting in their seats and doing everything possible to avoid meeting anyone else's gaze. When I break the taboo and stare at the man in the front row, he responds by bolting for the exit.
A palpable embarrassment fills the air, as if we are sitting in the waiting room of a sexually transmitted diseases clinic. Instead, we've paid our £4 and are expecting the duty medium - there's one on offer every day at 3.30 and 7.30 - to appear. Not literally. At least, I hope not. I'm jumpy enough already.
I'm feeling oddly uncomfortable about the prospect of going to a seance. It will be my first; and I had planned to remain a virgin. Then, prompted by the death of my Catholic mother, I started researching a book about the heaven she believed in, and felt it would have been absurd not to road-test the alternatives, including Conan Doyle's contention that we can contact those beyond the grave and be given proof positive of a glorious hereafter.
"All agree," he wrote in 1918 of his conversations with the dead, "that passing is usually both easy and painless and followed by an enormous reaction of peace and ease. The individual finds himself in a spirit body which is the exact counterpart of his old one, save that all disease, weakness or deformity has passed from it. This body stands or floats beside the old body and is conscious both of it and the surrounding people. At this moment the dead man is nearer to matter than he will ever be again."
It might prove an enticing message for some, but I fear an implied threat in this dark room.
The exit door is close to my seat and suddenly looks very inviting. My unusually clammy palms, linked defensively in front of my body, reveal my own mixed motives. I haven't, for instance, brought a notebook - just in case I find myself being guided by a spirit into automatic writing. The rational, 21st-century part of me tells me it is stuff and nonsense, but, to be honest, I am terrified of putting it to the test, lest it be proved to have some value. Logically, I must at some level believe in the claims.
My reaction is a good metaphor for contemporary attitudes to heaven. History, science and psychology point to it being a collective delusion, designed to take the edge off mortality and soften the random blows of fate in this life. On one level, most of us sign up to this randomness, and treat Heaven as some quaint medieval antique, nice to look at in paintings in art galleries, but utterly irrelevant to our lives. Yet when push comes to shove and the specialist tells us the test results are bad, the heaven that we have so far scorned suddenly becomes our next best hope. At which point, many find they have some core belief in a greater power and the trappings that go with it.
I imply no criticism. Heaven offers consolation by the bucket load, but then so, potentially, does spiritualism - though at least heaven requires some investment by way of imagination, faith or religious practice. Spiritualism, by contrast, requires only £4. Mark Twain memorably damned it as "a mean little 10 cent heaven". Allowing for inflation, that may be what I'm about to get.
At which stage, Joan, the duty medium, sweeps in. In my mind, I am expecting Madame Arcati, as played by Margaret Rutherford for Noel Coward. Instead, I get a Welsh housewife in her mid-fifties in a plain blue dress and neat white jacket. She might be about to do a cookery demonstration. She takes her place at what looks disconcertingly like an altar at the front of the room and launches into a brief and understandably partisan introduction to spiritualism. What catches my attention is less her bald statement that its claims have been scientifically proven, even though history shows unequivocally that they haven't, but rather her effort to place spiritualism firmly within the Christian tradition. Hers is a sanitised version of the long and uneasy relationship between the two. She even rounds off by leading us in a group prayer to God to encourage us all to be open.
While she does not use the word "heaven", preferring to talk of "those who live in the spirit" inhabiting "the astral plane", she nevertheless conjures up a heady cocktail of all the best audience-pleasing details of heaven's history - the promise of reunion with loved ones, the hum of constant activity ("You can even learn new skills there," she chimes, like an employment counsellor), the physical beauty of both the landscape and its inhabitants.
What she doesn't borrow from Christianity, however, is the difficult bit: the idea of judgement in death. That would mean some of her audience may be searching for loved ones who may not have made the cut at the Pearly Gates. Unlike them, we are all going to be satisfied in the next hour, it seems.
Joan explains that her own spirit guide has arrived at her shoulder. She even starts a little, as if he or she has just goosed her. Her eyes begin spinning like a roulette wheel. Someone's lucky number is about to come up. We all become tense.
"I want to come to the lady sitting at the back in the beautiful necklace." Joan is pointing elsewhere. The rest of the room breathes a collective sigh of relief. "I have a tall African gentleman here for you. Can you accept him?" The woman looks around confused, as if the said gentleman is about to appear through the curtains behind the makeshift altar like a guest on This is Your Life. "He has a special concern for you."
The woman is still straining to see him. Joan doesn't hang about waiting for her to catch up. "Can you hold on to that, think about it later, ask others?" The woman nods, utterly disorientated. "You've a birthday coming up." The woman has at last cottoned on. It's her granddaughter's birthday next month, she tells us all. It's a result.
It hasn't been an auspicious start, but Joan now alights on much more receptive raw material, a well-scrubbed young woman sitting eagerly in the front row. "I'm seeing the word healer above your head." The woman nods eagerly. There follows much talk of alternative remedies, health foods, t'ai chi, yoga and a long-lost grandfather who is playing the role of guardian angel. The blond head is bobbing enthusiastically at every take.
It is the high point of the session. Joan scores very few more hits as she darts around the room, falling victim often to her own stereotypes. Two Afro-Caribbean women are told that there is a spirit from the West Indies calling them, but they insist that they have lived in Birmingham for generations. An Indian-looking man is being contacted by someone sitting in a restaurant.
By the time Joan gets to me, I am not frightened. There is a father figure calling me from New England. My dad back in Birkenhead got his passport just two years ago at the age of 80, so she is way off there. Then she tries to read the words above my head and, after toying with technology - I've a big head - and teacher, she plumps for actor. In a narrow sense, she is right. My audition next week, she says, will go well and I will get the part that will make my name.
Yet there is something in the way she gives me my "messages" that means, instead of saying "actually, completely wrong", I find myself muttering "well, yes, sort of". In part, it's my middle-class anxiety about making a scene. Yet it is also that I would be easy game for any second-hand car dealer: Joan's technique is, I recognise, classic salesmanship. Never take no for an answer. Roll on relentlessly until you force your hearer to say yes.
But what exactly is Joan selling, and what is the profit? The second question is easier. A dozen people at £4 a head is £50 a hour. Then there is her final pitch, having given us all a taster, when she offers individual, in-depth sessions. The blond girl has her chequebook out at once. That will be another £50.
Yet it is still such a small-scale operation that I cannot quite believe it can be worth the effort unless the motivations are more complex. Transparent as Joan's deception is, there is no obvious malice in her, and I am quite happy to believe that her play-acting is born out of a genuine desire to help the walking wounded who turn up each day. With a touch of the frustrated actress thrown in. She may even delude herself that she is really hearing messages. The only damage done comes in terms of unfulfilled expectations.
Hence the continuing appeal of a seance - or, for that matter, spiritualism's more recent descendant, the Near Death Experience movement, where 13 million people in the United States claim to have had a peek at heaven while drifting in and out of life. Mainstream religion, long the arch promoter of heaven as either a perfect garden or a mystical union with the Almighty, has gone remarkably quiet about the hereafter. Pope John Paul II has described it only once during his long reign, and then, in July 1999, in bland terms as "a state of being" after death. The heaven that once fired imaginations, that seemed to promise an eternal reward for the injustices and sufferings of life, is no longer mentioned. Yet we still yearn for it. A recent Gallup poll had 70 per cent signing up to some kind of afterlife - not because it makes sense in our secular and scientific age, but because human beings are the only animals who have to live with the knowledge that they will die one day, and the promise of heaven allows for some comfort.
And who knows, after all, if there is anything in it? Joan certainly struck a chord with one member of her audience. The blond head is just turning happily out through the door when I spot, swinging from her hand, a white plastic bag - which was no doubt at her feet in the front row of the room - emblazoned with the logo of an alternative medicine shop.
Peter Stanford's new book, Heaven: a traveller's guide to the undiscovered country, is published by HarperCollins (£17.99). See Antonia Fraser's review, page 52