Sceptics are used to meeting strange people in odd places with TV cameras watching. So it did not seem unusual last month to be invited to test the supposed abilities of a psychic in a laboratory at University College London for a documentary "exploring spirituality in Britain".
You always expect the unexpected. But the truth on this occasion took unexpected to a new level. Testing psychics is difficult.
They often claim not to care about scientific proof, but love academic endorsements. Even if they utterly fail the tests, they may still try to extract credibility by talking about the institution or scientist while glossing over the dismal outcome. As a result, sceptics have to observe extreme care.
Academic qualifications are not sufficient by themselves to take on the task. Many serious researchers have fallen prey to simple magic tricks. I was one of five sceptics invited to take part in the experiment at UCL. The group included my friend Chris French, professor of psychology and head of the anomalistic psychology research unit at Goldsmiths College, University of London.
The ivory-suited psychic - "Shirley" - was undoubtedly the strangest any of us had ever met. He made louche suggestions about our "secret shame", Chris's being adultery, mine incontinence. And despite failing our tests, Shirley declared he had passed, making the wildest interpretations and loops of illogic imaginable.
As soon as I got out I phoned Chris: "Did you believe that guy?"
All five of us thought there was something wrong. Tony Youens, who runs the Association for Skeptical Enquiry, remarked: "If that man is a psychic, I'm a lion tamer."
Chris was the first to say he thought it was a spoof. I didn't believe him.
How could a group as insignificant as sceptics be the target of a TV wind-up? But a few hours later, through internet searching, networking and good journalistic techniques, we verified that Shirley was, in fact, comedian Marc Wootton recording a new series for the BBC.
Traditionally, there are three theories to explain a psychic's conviction that his abilities could pass a scientific test under proper observing conditions.
One: he really is psychic. As that is generally held to be scientifically impossible, it requires extraordinary proof.
Two: he is deluded. There are plenty of individuals who fit that description.
Three: he is doing magic tricks. That was what I was most concerned to guard against.
It was absolutely essential that Shirley could not get a look at the five personal facts I had been asked to write down, or copy the drawing I had made before he attempted to divine them.
I wrote the facts at home on my own stationery and sealed them in a foil-lined envelope. I finished the drawing alone in a bathroom stall, put it in a second foil-lined envelope and secreted both in my boot.
My focus in facing Shirley was to present scepticism as well as I could for the cameras and to make sure there were no tricks. There was none, just a fourth new theory to explain a psychic's conviction: that the entire production is a spoof.
Despite our humourless image, sceptics do not care if we personally look like idiots.
We have done Kilroy and late-night TV. We have listened politely to people in costume claiming to be Mary Queen of Scots reincarnate; whose plane crash dream foretold their brother's food poisoning; who are visited by aliens or angels; who think duck-billed platypus urine cured their cancer.
So we didn't laugh at Shirley. We told him politely that most psychics try to seem sympathetic.
We don't know what Wootton's goal is. But we care very much if scepticism is made to look foolish.
Wendy M. Grossman
Founding editor of The Skeptic magazine
Skeptics' website: www.skeptic.org.uk