Screaming skulls, bizarre Indian rope tricks (left), green children and "the changing face of alien abduction" - they're all in a day's work for the participants at the Fortean Times UnConvention, which this year celebrates the 50th anniversary of UFOlogy. Andy Roberts, who will be giving a talk on screaming skulls (see front cover) describes how certain cranial remains must, well, remain in particular houses, if they're not to unleash ghosts or other vindictive phenomena. "There are stories about skulls which have been dumped in the sea and made it back into the house by tea time," he breezes. "I think these stories probably have more to do with mythology than fact," Roberts chirps, "but, having said that, I wouldn't move one. I'd let sleeping dogs lie."

Author Duncan Lunan, another of the speakers at the conference and president of ASTRA, (the Association in Scotland to Research into Astronautics) says he "doesn't believe in UFOs", a strange admission from someone who spends his days validating the arrival of two alien tourists in 12th-century East Anglia. According to Lunan, Latin texts which describe how a green boy and girl emerged from a pit in the village of Woolpit describe an ancient alien visitation. Speaking a strange language, wearing weird clothing and initially refusing all food, the children were eventually persuaded to eat bean plants, "because they were the same colour as themselves".

"We are making it up on one level," Lunan admits, but before sceptics clap their hands together in glee, they should note that Lunan is not disowning the story, just describing the imaginative extrapolations that form one part of his research.

"In science fiction it's known as world building," explains Lunan. "You take what you know of an alien world and work around it a convincing model. The records state that the children came from a planet where the sun neither rose nor set. There was a very bright territory on the horizon. From that you can work out that this was a planet always facing the sun." Lunan is also happy to speculate about their means of transport: "There was a lot of odd stuff going on astronomically at the time. They didn't come in a flying saucer, but a physicist friend of mine said that conditions could have allowed them to be instantaneously transported." After three years research into genealogy and astronomy, Lunan is now not only "convinced" that the stories record a genuine "contact", but that a member of the current Cabinet is descended from the green girl ."The coincidences are too great," says Lunan. "At the time that it happened, Henry II had already annexed Woolpit and put his powerful Vice Chancellor in charge of this tiny village. Then, in 1173, he rushed back from a major war to garrison 300 crack troops there.

"Whatever it was that happened," he adds darkly "It's part of something much bigger, and Henry was in it up to his neck".

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