Shadows, tricks of the light and strange shapes that suddenly, somehow, appear more eerie than they usually do, come into their own at this time of the year when spirits roam. Creaking floorboards become groans, the wind sighs and the moon acquires a sickly, diseased look. As All Hallows, Halloween night, the eve of All Saints approaches, even cynics might think twice about that dark stretch of road that passes between a once grand but long deserted house and the churchyard with leaning tombstones bearing faint traces of inscriptions that are no longer legible. Shortcuts along dark lanes lose their appeal. You whistle louder, walk faster, sing a psalm, break into a run.
While most people might not be all that bothered finding themselves alone in a room with a pumpkin, a solitary candle illuminating its carved features, possibly making dancing shapes along the wall, the plaintive sound of the wind howling outside could prove unsettling. Particularly should that same wind happen to be blowing through the wet trees, perhaps causing a branch to scratch across the window-pane, like a desperate tapping. You think you saw someone at the window, what, two floors up? No, look again. Better still, don't. Every scary story you've ever read about insane clans comes to mind. There are weird faces appearing in the cracks in the ceiling plaster. What's the dog looking at? Why is he growling? How come the cat has arched her back? Is it a mouse? Hardly. As if on cue, there's a power cut.
So the people in the towns and the cities prepare for Halloween by buying funny masks and pinning paper skeletons up on doors, while stocking up on bags of nuts and tangerines. Every second child's face is painted, or hidden behind lurid green plastic. Witches are always popular, and a traditional broomstick is a sought-after accessory. Trick or treat is a form of insurance. Should you not have a supply of apples and sweets ready, you could find your car decorated with shaving foam - or worse.
But suburban Halloween, even in the presence of good storytellers skilled in terrifying their audiences, does not compare with the sound of flying hoof beats along a country road. Halloween belongs to the countryside, where night achieves absolute darkness.
Imagine Berlioz's Symphonie Fantastique, including Dream of a Witches' Sabbath, either competing with the wind or, better still, breaking the silence of a moonlit night when even the racing clouds appear crazed. See the ruined castle, high on the hill over there against the sky? Well, every Halloween night - or so they say - the ghost of a young girl in a white dress hurls herself off the roof, as she has done for the past 436 years.
Edgar Allan Poe was still a small boy when Washington Irving published The Legend of Sleepy Hollow. It remains the classic American ghost story. In it, the scrawny schoolteacher, Ichabod Crane, having been spurned by the ripe object of his desire, makes his way home on the pathetic old nag he has borrowed. The ancient yet perverse horse, answering to the ironic name of Gunpowder, does not believe in hurrying. But Crane's seething irritation on being rejected is quickly replaced by unease:
All the stories of ghosts and goblins that he had heard in the afternoon now came crowding upon his recollection. The night grew darker and darker; the stars seemed to sink deeper in the sky.
He notices the old tulip tree and its many gnarled, fantastic limbs. It's a tree with a history of ghostly connections.
Crane's own memory holds a store of tales gleaned from his reading of Cotton Mather's History of New England Witchcraft. Mather, author, scientist and bigot, had been a strong supporter of the Salem witch trials and saw evil lurking in most corners. But back to Crane's plight. Just beyond the haunted tree lies a haunted stream; the schoolteacher by now has entered the realm of terror.
On the margins of the brook, he beheld something huge, misshapen, black and towering. It stirred not, but seemed gathered up in the gloom, like some gigantic monster ready to spring upon the traveller.
A large horseman awaits and proceeds to match old Gunpowder's change of pace, from quick to slow and faster again. When he finally gets a good look at his unwelcome companion, Crane discovers that the stranger is headless, but notices a head balanced on the pommel of the saddle.
Irving's achievement was to make the very landscape appear complicit in the headless horseman's ghostly rides. Atmosphere as much as facts tell the tale.
That story was published more than 100 years after the notorious Salem witch trials in 1692 had filled the women of Puritan Massachusetts with fear. Restless spirits, usually the victims of violent deaths, often tragic lovers and, particularly, betrayed women, not forgetting monarchs, monks butchered in raided abbeys and slain soldiers, dominate our ideas of souls likely to become ghosts. But ghostly or supernatural doings in Europe during the Middle Ages, with its emerging religious conflicts and obsession with heresies, quickly became associated with evil. Even mild eccentricity was sufficient reason for a woman to be accused of sleeping with the devil.
Judging by the wealth of wood carvings depicting sexual congress between Lucifer and, at times, more than one gleeful female, such activities were widespread, or at least thought to be. Lone women were regarded warily in medieval Europe.
Religious disputes tore Europe asunder; even the Knights Templars, a military religious order which was initially the protector of pilgrims, in time the banker of Europe, fell prey. Charges of heresy soon followed. The last grand master was burned as a heretic in France in 1314. In some parts of Europe, a particular form of persecution dominated.
It had to do with magic, the black arts or at least charges of such. The Anglo-Saxon word "wicca"/"wicce" originally referred to someone who used magic, whether for good or evil. The word then evolved further into "witch", a person engaged in evil.
Robert Thurston, a professor of history in Ohio, has pursued this subject with much enthusiasm in Witch, Wicce, Mother Goose. It is fascinating to observe how such trends move in historical waves. It was not enough to blame the plague or the Black Death on rats, there had to be other culprits. Enter the witch, usually female and always bad - in keeping with the poor image of women, particularly held by the Church, during that period.
The first example in Europe of what would become a witch trial took place in Kilkenny in 1324. Dame Alice Kyteler was wealthy, had buried three husbands and was on her fourth when Bishop Richard Ledrede saw similarities between her and the Knights Templars. Kyteler, who was then in her 60s, was charged with engaging in bizarre rituals and creating spells using animal parts and the hair of the dead all mashed up in the skull of a decapitated thief. The good dame and her followers, mostly her servants, were charged with killing previous husbands and being at work on the death of the fourth.
She was also accused of having a familiar in the form of a large black cat, sometimes a black dog, at times a black man.
Kyteler fled the scene. One of her servants was burnt. But the bishop soon fell out of favour. Kyteler's family were powerful, and he was soon banished back to France.
Witch trials in Europe peaked between 1580 and 1630, mainly in Switzerland, France, Italy and Germany. Few occurred in Scotland prior to 1590, while in England they happened between 1560 and 1580. The year 1612 was also a busy one, as were the 1640s. Swedish witches had a black time in the 1670s. The last recorded European witch-burning took place in Switzerland in 1782, some 90 years after the events at Salem.
Old, neglected churchyards, where even the yew trees look weary, are so atmospheric that a ghost among the crumbling gravestones would be merely a bonus. You don't have to be a ghost-hunter to be conscious of spirits and the restless dead.
Anyone given to visiting old houses and churches, ruined castles and abbeys, woods, deserted beaches or archaeological sites, whether stone circles or passage graves, would have to be aware of the presence of the dead, of the generations contained within the history of a site.
I remember staking out a churchyard in Newcastle, Co Wicklow, near where the local castle had its ghost, a girl thwarted in love who had been repeating her suicide for several hundred years. I saw something and have since never run as fast.
Ireland, with its vengeful "little people" and multitude of ring forts, testifying to early settlement but also to the power of myth and oral tradition, has a supernatural dimension evident in many place names.
Annascaul, Co Kerry or Abhainn na Scβil (the river of the phantom); Glennascaul, Co Galway or Gleann an Scail (the valley of the phantom); Drumarraght, outside Maguiresbridge, Co Fermanagh, or Droim Aracht (the ridge of the apparition) - there are many stories about witches being turned into large white stones. Connemara, Co Kerry and Co Tipperary are rich in ghosts. The Famine created its own store of supernatural tales.
Haunted Britain and Ireland, a pictorial account by Richard Jones, of 130 sites in these islands, suggests Mary Queen of Scots is the most busy spectre currently at work. Cardinal Wolsey's great palace, Hampton Court, boasts at least 30 ghosts, including three of Henry VIII's wives, Anne Boleyn, Jane Seymour and Catherine Howard. England has so many ghosts they must have a union.
Among Ireland's 12 entries is Leap Castle, Co Offaly, once dubbed the most haunted house in Ireland. This medieval tower house with 19th-century extensions is now owned by a traditional musician who has been restoring it and deals with US agents for tour parties interested in banquets. One evening recently I arrived unannounced and was clearly not as welcome as a visiting spirit or a US tourist. But Leap Castle, now a home, is far less terrifying than the 17th-century Burke Glinsk Castle in Connemara.
There are any number of sites capable of chilling your soul of a Halloween night, from Loughcrew passage tomb cemetery to the once mighty Dunamase Castle on a hilltop in Co Laois. Also in Co Laois stands Lea Castle. Once one of the largest Norman castles in Ireland, this great ruin, with its ivy, wall walks, screaming crows and the occasional bat, has a life of its own, in the dark . . .
Ireland's castles have a bloody history of conquest, power and mortal decline. Their ruins are atmospheric. Still, no place quite challenges an ancient churchyard at midnight, on Halloween. Just wait and watch and . . . what's that over there?
Witch, Wicce, Mother Goose by Robert W. Thurston is published by Longman (£20 in UK). Haunted Britain and Ireland by Richard Jones is publshed by New Holland (£19.99 in UK)