The bodies under the floorboards

In Orkney, folk memory is tenacious. For eight decades, nobody had bothered the police with persistent rumours about the polite prostitute and her granite-hard mother who lived at St Olaf's Cottage at the beginning of last century. Such things were not freely discussed. But last December, when tiny human bones were found beneath the floorboards of the little stone dwelling, it seemed that everyone knew the truth. They were the remains of Violet Gray's illegitimate children. Her mother, the terrifying and socially ambitious Tamima, had drowned four of them before the poor devils had time to draw their first breath. They had gone from womb to rusty iron bucket like the guts of the fish Orcadian women once filleted for a living, and with no more thought.

Surviving descendants of the infanticidal Grays confirmed the tale. Officers of the Northern Constabulary disclosed their "strong suspicion" that folk memory was right. Gordon Gray, Violet's sole surviving child, had been spared because he had been a breach baby; a doctor had been required to deliver him. Tamima could not risk murdering Gordon because his existence was known to officialdom, though the legend insists that she wanted to. Michael, son of the late Gordon, heard the story from his father.

There are a few anomalies. The Gray family say Tamima murdered four of her daughter's offspring. The police have found the remains of only three. Hushed gossip insists that there are really 11 little corpses, all killed by Tamima, though surely not all products of Violet's occasional pursuit of the oldest profession. Tamima Gray wanted both wealth and status. She married a gold prospector and condoned her daughter's immoral earnings, but she would not nurture illegitimate progeny. That would have attracted the ire of the Kirk Session. Inconceivable. Her father had been a lay minister.

The impression is of an open-and-shut case. An evil, twisted old woman gave social status a higher priority than life. Born and raised in a still pre-modern community, where the church, not a police force, imposed the law, Tamima Gray still feared humiliation by her peers more than eternal damnation. Possibly; but the simple narrative is divorced from its context. Orcadians who now condemn Tamima as a serial killer are the very ones who claim to have known all along, but said nothing. Is there another force at work, a desire to obscure bizarre traditions that surrounded pregnancy and childbirth in the islands well into the 20th century and made infanticide, particularly by unmarried mothers, common enough to offer a different explanation for the crimes of Tamima and Violet Gray?

The name of the cottage provides a clue. Saint Olaf was King Olaf II of Norway (1015-1030), a Viking convert to Christianity and monarch of the country that claimed Orkney as a fiefdom from 875 to 1762. For long after that, Orcadians considered themselves more Norse than Scottish. Their adoption of the laws and teachings of the Church of Scotland was mingled with fierce loyalty to ancient Norse myths and practices. These made it possible for women who became pregnant outside marriage to regard their babies as less than human, even deserving of instant death.

An academic study of infanticidal mothers in neighbouring Shetland between 1699 and 1899 has been carried out by Lynn Abrams, a historian at the University of Glasgow. Dr Abrams' work shows that 40 allegations of child murder and concealment of pregnancy were investigated by the Shetland authorities. Many involved identical evidence. The women were not married. They persistently denied that they were pregnant. They gave birth in secret, often denying that they had experienced labour pain. When forced to confess by church elders or neighbours who would squeeze their breasts to prove the women were lactating, the unfortunate girls would either swear their child had been born dead or maintain the fiction that what they had delivered was not a child but, as the unfortunate Margaret Walterson told her interrogators in May 1855, "something else – some burden with which she had no previous acquaintance".

In 1899, Gina Skaar, a Norwegian housemaid, disposed of her newborn child by throwing it into the sea. She was found in a bed "saturated with blood" but told the women who came to question her that her periods had stopped for 14 months and "had come on again". Another terrified girl, Mary Dempster, told a doctor who was certain she had given birth that she had disposed of nothing more than clotted blood.

Modern psychology has a term for this behaviour. It calls it "splitting", a mental condition in which a woman terrified of the stigma of illegitimacy or pregnant by virtue of a fleeting, incestuous or violent relationship entirely disassociates herself from the existence of her child. Such women can convince themselves that they are not really pregnant. The evidence is rigorous. Such a syndrome exists. It merits sympathy, not condemnation. But it is very rare.

The frequency with which such tales emerge in Orkney and Shetland invites an alternative interpretation. It is rooted in Norse lore and unique local adaptations of traditional Scandinavian customs and beliefs. Sigurd Towrie of Orkney's weekly newspaper, The Orcadian, is the latest in countless generations of Towries to live in the islands. He has made himself an expert in the history and traditions of his ancestral homeland.

Towrie writes that in Orkney childbirth was "and to a certain extent still is... a time of uncertainty and fear surrounded by spells, incantations, prohibitions and precautions". The most rigorous of these pre-modern superstitions is "the absolute requirement to conceal a pregnancy – an act deemed necessary to avoid attracting the attention of 'trows' or fairy folk".

Orcadian lore dictates that if these supernatural creatures detect an impending birth they will harm the mother and her unborn child. Towrie explains that until the early part of the 20th century locals believed that "where a child sickened or was seen not to thrive, it was thought that the precautions against the trows had not been enough. The healthy young infant had surely been spirited away and the creature in its place was a trowie changeling."

Trows? Changelings? Surely this is medieval mumbo-jumbo. It must have been long forgotten by the time Violet Gray was conceiving unwanted children in sexual encounters with soldiers and local tradesmen. The archives of The Scotsman newspaper, based in cosmopolitan Edinburgh not the Orcadian capital Kirkwall, suggest otherwise. A correspondent writing in 1893 described uncritically the activities of Orkney's trows, declaring that they were "incredibly skillful in making images of human beings and animals. The stocks or likenesses they left in a bed when they removed a man, woman or child defied detection."

Sigurd Towrie explains that, in some circumstances, "this belief distanced parents from the child – in their eyes, after all, it was not theirs but an unnatural creature". He, and other folklorists, acknowledge that the residue of such beliefs was still alive in Orkney as late as the 1930s.

Do such fables have any part to play in explaining the murders at St Olaf's Cottage? The imperative to conceal pregnancy lends itself to an understanding of how Violet was able to conceive and carry children without the authorities ever investigating why they never emerged into the world. Traditional belief that there were such things as children who were not really children may explain why those who gossiped about Violet Gray's missing babies never pried further into what had happened to them.

Orkney police say they have a responsibility to "peel away" the rumours and folklore that have surrounded the house for years. Inspector Paul Eddington of the Kirkwall force says: "We are not carrying out a murder enquiry. We are currently involved in information gathering to pull all the pieces of this puzzle together. These bones cannot be proved to have come from any particular member of a family, as they are too small and fragmented, and to suggest ownership would be insensitive."

So, the official verdict is that it is not yet known whether the tiny bodies are those of children born of Violet Gray. They may be. They may have been murdered at birth by her mother. But if that did happen, it is possible to deduce motives more complex than pure malice.

Perhaps Tamima Gray and her daughter acted only out of a desire to avoid social stigma and escape censure by church and state. Infanticide for these reasons occurred throughout Scotland in the 18th and 19th centuries. It was sufficiently prevalent that, in 1809, the law was changed to create an offence less grave than murder. Statute interpreted "concealment of pregnancy and failure to call for assistance at the birth" as an offence that warranted no more than two years in prison. Sheriff court records show that many women, who modern forensic science and medical supervision would have shown to have given birth to live babies, were able to use this law to claim stillbirth and obtain leniency.

That certainly happened in Orkney where, even in Violet Gray's day, doctors hardly ever attended births. Is it possible that the surprising tolerance of the law permitted the endurance of local rites in which women giving birth to unwanted babies convinced them- selves and their peers that these were not children at all and so killed their offspring without ever considering the deed criminal?

If that was what Tamima and Violet Gray believed, they were not the only Orcadians of the time to excuse criminality as a macabre form of tradition. Some even believe that Tamima was a version of the "wise woman" or "howdie" who attended legitimate births but could also advise on how to get rid of unwanted children. One contemporary Orcadian, the writer Magnus Linklater, has suggested a less compassionate name for these characters: witch.