On the morning of 21 October 1966, a dark, glistening wave of coal waste burst out of the hillside above the Welsh village of Aberfan and poured down. People later compared the roar of the collapsing mine tip to a low-flying jet aircraft or thunder or a runaway train. At first, sheep, hedges, cattle, a farmhouse with three people inside were smothered. Then the wave reached Pantglas junior school and Pantglas county secondary school, burying the former, which was full of children answering the register. One hundred and forty-four people were killed by the tip slide in Aberfan, 116 of them children, mostly between the ages of seven and 10. In the aftermath, a roadblock was set up to control access to the disaster, but more or less anyone in a uniform or an official-looking car could find a way through. During the morning of 22 October, a green Ford Zephyr nosed its way into the village. At the wheel was John Barker, a 42-year-old psychiatrist at Shelton hospital near Shrewsbury with a keen interest in unusual mental conditions. Barker was tall and broad and dressed in a suit and tie. At the time, he was working on a book about whether it was possible to be frightened to death. In the early news reports from Aberfan, Barker had heard that a boy had escaped from the school unharmed but later died of shock. The psychiatrist had come to investigate, but realised he had arrived too soon. When Barker reached the village, victims were still being dug out. “I soon realised it would have been quite inopportune to make any inquiries about this child,” he wrote afterwards. The devastation reminded Barker of the blitz, when he had been a teenager, growing up in south London, but the loss of life in Aberfan was worse for being so concentrated and the dead so young. “Parents who had lost their children were standing in the street, looking stunned and hopeless and many were still weeping. There was hardly anybody I encountered who had not lost someone.” Voyeurs and outsiders who came to Aberfan without good reason were easy to identify. Policemen who stood around drinking tea were shouted at. Someone threw a tobacco tin at a photographer and broke his camera flash. During the course of the day, a steady drizzle came down, soaking the hundreds of rescuers, muddying the streets, which were already inches deep in muck, and raising fears that the tip could suddenly fall again, causing another calamity. The village was dreadfully tense. But Barker did not get back in his car and drive away. He had long been interested in subjects that struck others as macabre or inexplicable. He was, in every outward sense, an orthodox psychiatrist. He had studied at the University of Cambridge and at St George’s Medical School, in London. But he also chafed at the limits of his field. Barker was a member of Britain’s Society for Psychical Research, which was founded in 1882 to investigate the paranormal, and for some years had been interested in the problem of precognition and people who seemed to know what was going to happen to them before it actually did. Talking to witnesses, he was struck by “several strange and pathetic incidents” connected to the disaster. A school bus, carrying children from Merthyr Vale, had been delayed by fog and reached the site after the tip fell. Their lateness saved their lives. A boy had overslept, apparently for the first time in his life, and was sent hurrying to school by his mother, in tears; he was crushed. Inane, unthinking decisions in the moments before the waste came down – a cup of tea before starting work, looking the wrong way, resting on a wall – spared lives and ended others. Barker was interested in the nature of those decisions and what prompted them. Did people have rational fears or inexplicable knowledge? The dark, unnatural tips above Aberfan had long played on local people’s minds. Bereaved families also spoke of dreams and portents. Weeks after the accident, the mother of an eight-year-old boy named Paul Davies, who died in Pantglas school, found a drawing of massed figures digging in the hillside under the words “The end”, which he had made the night before the slide. In the days after his visit to Aberfan, Barker came up with an idea for an unusual study. Given the singular nature of the disaster and its total penetration of the national consciousness, he decided to gather as many premonitions as possible of the event and to investigate the people who had them. Barker wrote to Peter Fairley, the science editor of London’s Evening Standard newspaper, and asked him to publicise the idea. On 28 October, Fairley carried Barker’s appeal in his World of Science column. “Did anyone have a genuine premonition before the coal tip fell on Aberfan? That is what a senior British psychiatrist would like to know,” Fairley wrote. The article described the kinds of vision that Barker was interested in: “a vivid dream”, “a vivid waking impression”, “telepathy at the time of the disaster (affecting someone miles away)” and “clairvoyance”. Barker received 76 replies to his Aberfan appeal. Two nights before the disaster, a 63-year-old man named J Arthur Taylor, from Stacksteads, a village on the edge of the Lancashire moors, dreamed that he was in Pontypridd, in south Wales. He had not been in the town for many years and he was trying to buy a book. He faced a large machine with buttons. “Now I have never seen a computer. This may have been one; I just don’t know,” Taylor wrote. “Then, all of a sudden, while I was standing by this big machine, I looked up and saw ABERFAN written as if suspended in white lettering against a black background. This seemed to last some minutes. Then I turned and looked the other way and I saw through a window rows of houses and everything seemed derelict and desolate.” Taylor did not recognise the word, even though he had driven past the village countless times, until he heard it on the radio on the day of the disaster. In Plymouth, the evening before the coal slide, Constance Milder had a vision at a spiritualist meeting. Milder, who was 47, told six witnesses that she saw an old schoolhouse, a Welsh miner, and “an avalanche of coal” rushing down a mountain. “At the bottom of this mountain of hurtling coal was a little boy with a long fringe looking absolutely terrified to death. Then for quite a while I ‘saw’ rescue operations taking place. I had an impression that the little boy was left behind and saved. He looked so grief-stricken.” Milder recognised the boy later on the evening news. A man in Kent was convinced for days before the Aberfan accident that there would be a national disaster on the Friday. “It came to me as strongly as might come the thought that you have forgotten that it was your wife’s birthday tomorrow,” wrote RJ Wallington, of Rochester. When he arrived at work on 21 October, he told his secretary: “Today’s the day.” Barker wrote back to the percipients, as he called them, asking for details and witnesses. Of the 60 plausible premonitions, there was evidence that 22 were described before the mine tip began to move. The material convinced Barker that precognition was not unusual among the general population – he speculated that it might be as common as left-handedness. In the weeks before Christmas, Fairley and Barker approached Charles Wintour, the editor of the Evening Standard, to open what they called a Premonitions Bureau. For a year, readers of the newspaper would be invited to send in their dreams and forebodings, which would be collated and then compared with actual happenings around the world. Wintour agreed to the experiment. Fairley devised an 11-point scoring system for the predictions: five points for unusualness, five points for accuracy and one point for timing. The Premonitions Bureau was not the first attempt to capture the visions of the British public. In the late 1920s, JW Dunne, an aircraft designer, wrote a popular book called An Experiment With Time that combined an account of his own precognitive dreams with a discussion of relativity theory and quantum physics. In 1902, Dunne was a young soldier serving in the Boer war when he dreamed of a volcano about to explode on a French colonial island, which would kill 4,000 people. A few weeks later, he got hold of a Daily Telegraph, which reported the loss of 40,000 lives after the eruption of Mont Pelée, on the Caribbean island of Martinique, and read about his dream in print. “I was out by a nought,” Dunne reflected. Premonitions, banal and tremendous, stalked him for years. Dunne’s response was unsentimental. “No one, I imagine, can derive any considerable pleasure from the supposition that he is a freak,” he wrote. By the end of the first world war, Dunne was consoled by advances in quantum mechanics that suggested the old order of time was collapsing. “That, already, was in the melting pot,” he wrote. “Modern science had put it there – and was wondering what to do next.” Dunne’s own theory about how time worked, which he called serialism, was hard to follow, but An Experiment With Time was influential because it encouraged thousands of readers to keep dream diaries and to see if their presentiments materialised. Dunne emphasised that we should pay attention to trivial flashes of the future as well as things that seemed important. He liked to sit in the library of his club, pick up a novel, glance at the name of the protagonist and then jot down thoughts and images that came to him, to see if they predicted the plot. One day, Dunne picked up a book by JC Snaith, a cricketer turned popular author, but nothing came to him except a peculiar image of a plain-black, entirely straight umbrella, standing vertical – its handle resting on the pavement – outside the Piccadilly Hotel. The next day, Dunne found himself on a bus as it approached the hotel and noticed a figure walking along: “It was an old lady, dressed in a freakish, very early-Victorian, black costume, poke bonnet and all. She carried an umbrella in which the handle was merely a plain, thin, unpolished extension of the main stick … She was using this umbrella – closed, of course – as a walking stick, grasping it pilgrim’s staff fashion. But she had it upside down. She was holding it by the ferrule end, and was pounding along towards the hotel with the handle on the pavement.” While Dunne’s work was popular in Britain, 20th-century physics and psychology catalysed similar interest in prophetic dreams elsewhere in Europe. In 1933, a Jewish journalist in Berlin, Charlotte Beradt, began secretly writing down the dreams of German citizens soon after the Nazis came to power. Three days after Hitler was elected chancellor, a factory owner dreamed that it took him half an hour of excruciating effort to raise his arm in salute during a visit by Joseph Goebbels. A 30-year-old woman dreamed that all the street signs in her neighbourhood had been replaced by posters with a list of 20 words that it was now forbidden to say. The list started with “Lord” and ended with “I”. Later, the same woman dreamed that a squad of policemen hauled her out of a performance of The Magic Flute because a thought-reading machine – “it was electric, a maze of wires” – had registered her associating Hitler with the word “devil”, when it was sung by Papageno and Monostatos during the opera. Beradt collected around 300 dreams. Many involved bureaucratic absurdity – The Decree of the Seventeenth of this Month on the Abolition of Walls; A Regulation Prohibiting Residual Bourgeois Tendencies – which prefigured the totalitarian intentions of the regime. A Jewish lawyer dreamed that he was crossing Lapland to reach “the last country on Earth where Jews are still tolerated”, but a smiling border official threw his passport into the snow. A green, safe land lay tantalisingly out of reach. It was still 1935. Beradt posted her notes to friends or hid them in books, and published them after the war. In The Third Reich of Dreams, she wrote that these “diaries of the night” seemed “to record seismographically the slightest effects of political events on the psyche”. They were raw, untouched by hindsight and possibly prophetic for that reason. “Dream imagery might thus help to describe the structure of a reality that was just on the verge of becoming a nightmare,” Beradt wrote. In 1940, when Britain was threatened with invasion, the playwright JB Priestley delivered regular Sunday evening radio talks on the BBC, called Postscripts, which were heard by a third of the British population. Priestley was from Bradford. He evinced a patriotic longing from the scattered notes of birdsong or a day trip to the seaside. He was also a follower of Dunne; Priestley described himself as “time-haunted”. In the early 1930s, the playwright had travelled to the American west. Early one morning, he stood by a railing on the South Rim of the Grand Canyon, with the landscape shrouded in mist. Suddenly the mist lifted, the colours shone, and Priestley recognised the railing, the sky and the canyon from a vivid dream that he remembered from years before. (In the dream, he had been sitting in a theatre when the curtain lifted and displayed precisely the same scene.) Priestley’s plays, such as Time and the Conways and, later, An Inspector Calls, reflected his preoccupation with the order of time. He helped to publicise Jung’s idea of synchronicity, which proposed that events could be linked by meaning rather than causation, in the English-speaking world. In March 1963, a few months before Barker arrived at Shelton, Priestley appeared on the BBC arts programme Monitor to talk about time. Priestley was almost 70 years old and had become a beloved national figure. He equated a strict, materialist reading of how time passes – each second of our lives flowing remorselessly, one after the other, until death – with the intellectual barrenness of capitalist consumption. “The moment does not matter because it is only another little step towards final oblivion,” Priestley wrote in Man and Time, which was published the following year. “It is all a tale told by an idiot.” Priestley was struck by how earlier and non-western cultures were comfortable with more sophisticated notions of time. He proposed a model of three concurrent times (the present, the unconscious and a collective unconscious), which was a fusion of Jungian and psychical ideas, not unlike Barker’s. Priestley compared living within the modern understanding of time to balancing on a rope that was fraying at both ends: scientists knew that time was unpredictable at both the planetary scale, because of relativity, and the subatomic scale, because of quantum physics. So why should it flow steadily, ceaselessly, through human lives? Priestley described “a world dominated by the worst idea of time men have ever had”. Man and Time was part confessional, part manifesto. Priestley implored society to step off the “inexorable conveyor-belt to nothingness”. During his BBC broadcast in 1963, the interviewer, Huw Wheldon, invited viewers to send in their own unusual experiences of time. Priestley received around 1,500 letters, of which around a third appeared to come from followers of Dunne. Barker wanted the bureau to be more than another collection of anecdotes. The Aberfan material had convinced him that it was no longer necessary to prove the existence of precognition. In an article for the Medical News in January 1967, two weeks into the experiment, Barker claimed that there were now more than 10,000 incidents recorded in parapsychology journals. “We should instead set about trying to harness and utilise it with a view to preventing further disasters,” he wrote. Like Beradt in Nazi Germany, Barker used the language of seismology to describe mental processes that might be operating at a deep level within the collective subconscious. He wanted an instrument that was sensitive enough to capture intimations that were otherwise impossible to detect. He envisaged the fully fledged Premonitions Bureau as a “central clearing house to which the public could always write or telephone should they experience any premonitions, particularly those which they felt were related to future catastrophes”. Over time, the Premonitions Bureau would become a databank for the nation’s dreams and visions – “mass premonitions”, Barker later called them – and issue alerts based on the visions it received. “Ideally the system would need to be linked with a computer, to help exclude trivial, misleading or false information … With practice, it should be possible to detect patterns or peaks which might even suggest the nature and possible date, time and place of a disaster so that an official early warning could then be issued. “There might be numerous false alarms, particularly in the early stages, when the operators were inexperienced,” Barker conceded. He recognised that the bureau also faced a version of the quandary that haunted Jonah in the Old Testament. God asked Jonah to prophesy the destruction of Nineveh. But Jonah reasoned that if the people of Nineveh believed his warning and repented, God would forgive them and Nineveh would not be destroyed after all. Jonah’s prophecy would turn out to be false, and he would look like a fool. Befuddled and ashamed, Jonah ran away and ended up inside a whale. If a calamity is averted, how can it generate a vision to precede it? “Theoretically, there might be no premonitions since no disaster would have occurred,” Barker acknowledged. But it was worth a shot. There were plenty of cases of premonitions that appeared to have helped avoid certain disasters in the past. “If only one major catastrophe could be shown to have been prevented by this means,” Barker wrote in a paper for the Society for Psychical Research later that year, “the project would have more than justified itself, perhaps for all time.” The bureau got its first major hit in the spring of 1967. At 6am on 21 March, the phone rang in the dining room at Barnfield, Barker’s home in the village of Yockleton, outside Shrewsbury. He went downstairs and answered. It was Alan Hencher, a post office switchboard operator, one of the Aberfan seers who claimed to experience physical sensations before a disaster. “I was hoping not to have to ring you,” Hencher said. “But now I feel I must.” Hencher was coming off a night shift and was calling to predict a plane crash. Barker made notes on a piece of Shelton hospital letterhead. Hencher was upset. He had a vision of a Caravelle, a French-built passenger jet, experiencing problems soon after takeoff. “It is coming over mountains. It is going to radio it is in trouble. Then it will cut out – nothing.” Hencher said there would be 123 or 124 people on board (“? say 124”, Barker jotted down) and that only one person would survive, “in a very poor condition”. Hencher couldn’t tell where the crash was going to happen but he had had the feeling for the last two or three days. It was as if someone on the aircraft was trying to communicate with him. They were trying to make peace. “While I am talking to you, I have a vision of Christ,” Hencher told Barker. He could see a pair of statues and was directed to the crash by a light flashing on and off. Barker’s notes ran to the bottom of the page and into the corner. On the other side of the paper, he noted that he called Hencher back later for more details, but there were none. It was an hour before dawn, on a Tuesday morning. After being woken by Hencher’s telephone call that night, Barker passed the prediction on to the Evening Standard. On 11 April, he and Fairley appeared on Late Night Line-Up, a chatshow on BBC Two, to publicise the bureau. Nine days later, a turboprop Britannia passenger aircraft carrying 130 people attempted to land in Nicosia, Cyprus, during a thunderstorm. The plane, which belonged to Globe Air, a new low-cost Swiss charter airline, was on its way from Bangkok to Basel, carrying mostly Swiss and German holidaymakers. It had refuelled in India and was on route to its penultimate stop, in Cairo, when the pilots were advised the airport was closed because of heavy rain. The flight plan suggested Beirut as the back-up option but the captain, a British pilot named Michael Muller, decided to make an unscheduled landing in Cyprus, despite the bad weather. By the time the plane reached the island, it had been in the air for almost 10 hours. Muller and his co-pilot were almost three hours over their time limits at the controls. At 11.10pm, the aircraft was cleared to land at Nicosia, but came in a little high. Muller requested permission to make a low circuit of the airport and try again. The control tower glimpsed the plane, its landing lights flashing through the low cloud, before it wheeled to the south and clipped a wing on the side of a hill – 22 feet from the summit – rolled over, broke into pieces and caught fire. “124 DIE IN AIRLINER” the Evening Standard reported on its front page the following morning. (The final death toll was 126; two people who survived the initial impact were taken to a nearby UN field hospital, where they died.) At the time, the Nicosia crash was the sixth worst aviation accident in history. Fairley and Barker noticed the similarities with Hencher’s prediction immediately. The Evening Standard published an account of Hencher’s premonition alongside the news coverage that day. “The Incredible Story of the Man Who Dreamed Disaster” the headline read. An accompanying photograph showed Archbishop Makarios, the island’s Greek Cypriot president, picking through the wreckage. Hencher was a gaunt 44-year-old man who lived with his parents in a council house in Dagenham, in Essex, now part of London. The family had moved out of the East End of London before the war. Percy, Alan’s father, had worked as a local government clerk. His mother, Rosina, stayed at home to look after the couple’s three sons. The eldest, Eric, had served in the commandos in Burma; the youngest, Ken, was a professional footballer for Millwall FC in the 50s before leaving the sport to become a customs and excise official. Alan, who had once been an apprentice to an optician, was the odd boy out. The Hencher family liked a drink; Alan preferred to read. He was affable but serious. He was proud of his collection of history books. In 1949, when he was 26, he suffered a head injury in a car accident and was unconscious for four days. His precognitive ability began soon after. “He was just different to the rest of them,” his niece, Lynne, recalled. “He was very intense about everything.” On the day of the plane crash, Fairley tried to call Hencher from the Evening Standard but failed to get through. Barker had arranged to speak to Hencher the following day. Shortly before 1am, the telephone in the dining room at Barnfield rang again. Barker came downstairs. It was the night-time switchboard operator at Shelton. Hencher had called the hospital, trying to reach Barker. He sounded agitated and the operator wanted to put him through. The future of the Premonitions Bureau – and Barker himself – changed direction when Hencher came on the line. As the psychiatrist wrote in an anguished memo the following day: “I suppose anybody who plays about with precognition in this way to some extent sticks his neck out and must accept what he gets.” In the darkness of the dining room, Hencher told Barker that he was concerned for his safety. He had been worried about him all day – that there might be some kind of accident. When Hencher thought of Barker, his mind filled with something black. He urged the psychiatrist to check his gas supply. But Barnfield didn’t have a gas supply. “Have you a dark car?” Hencher asked. Barker’s Zephyr was dark green. “Be very careful,” Hencher warned. “Look after yourself.” Barker asked Hencher if he was telling him that his life was now in danger. “Yes,” the seer replied. This is an extract from The Premonitions Bureau by Sam Knight, published by Faber & Faber at £14.99 on 5 May. To support the Guardian and the Observer, order your copy at guardianbookshop.com. Delivery charges may apply.