The Andover Poltergeist: "Eric Waters" and the responsive raps, 1974

Andover is a market town in Hampshire. In 1974 a family the records call the Andrews lived there, in a council-owned terraced house built in the 1960s. Mr and Mrs Andrews had six children. Theresa, 12, shared a bedroom with her sister Maria, 20. The room sat directly above an alleyway at the end of the row.

Good Friday, 12 April 1974. The sisters lay quietly in bed. Light tapping came from the wall beside Theresa's bed. That wall adjoined the house next door, so the family first suspected the neighbours. Then the girls asked, "Is anybody there?"

The knocks answered. One for yes. Two for no. Three for don't know. Letters came by their place in the alphabet, five knocks for E, thirteen for M. The source gave a name. Eric Waters. A young boy, it said, whose bones lay beneath the house. Soon the raps were keeping the family awake at night. When Kevin, 19, called Eric a liar, very loud knocking followed.

Barrie G. Colvin of the Society for Psychical Research found the case in the local paper and made nine visits between 28 April and 10 June 1974. He watched Theresa lie still on her bed, sometimes face down and sometimes under the covers, in good light. On 2 May he put his hand on the headboard as, in his words, "Eric rapped progressively louder on the headboard and I could clearly feel the vibration." On request, the raps moved to the metal bed frame at a higher tone. He held up a playing card and reported, "Four slow but definite raps were heard."

On 7 May, about twenty people gathered in the passageway below the bedroom. "The banging sounds were quite deafening," Colvin wrote. Standing at least 50 yards away, he could still hear them. Then he and the crowd placed their hands on the outside wall. "The vibration was felt by everyone."

On 7 June the scientist Dr Reinhart Schiffauer came as an open-minded sceptic, with high-speed and infrared cameras. Nothing unusual appeared on the film. That day Eric spelled a last message. "I am here to rest and stop my bones from rotting." On 10 June Theresa announced that "Eric had gone, and gone for ever."

Colvin went looking for the boy. He checked the two main Waters families around Andover, the birth and death registers from 1837 onwards, and local historians. An appeal in the Southern Evening Echo drew no responses. No floorboards were lifted. No bones were found. "There was no reference to an Eric Waters in the Andover area."

The obvious sceptical reading is that a child can make raps with a hand, a foot or the bed, and Colvin weighed that against what he saw. On request, the raps left the party wall and were felt through wood and metal. A tape left running alone in the room showed Eric knocking the correct count even when Theresa misread a letter. His conclusion: "the 'living person' hypothesis is the more probable interpretation." His tentative view was recurrent spontaneous psychokinesis centred on Theresa.

Colvin published the full report in the Journal of the SPR in 2008. Andover also prompted his study of recorded poltergeist raps, from Sauchie in 1960 to Euston Square in 2000, Enfield among them. Unexplained raps, he found, build to a peak before they decay. Ordinary knocks do not.