In 1944, medium Helen Duncan became the last woman in Britain to be convicted of witchcraft when one of her seances exposed a government attempt to cover up the deaths of 861 sailors. Now, campaigners aim to clear her name It started much the same as her other seances. With a chilling moan and strange white substance leaking from her mouth, Helen Duncan began communicating with the dead... But suddenly, the eerie calm was pierced by a police whistle and officers piled into the house, in Portsmouth, Hants, to arrest Britain's top medium. The following morning Helen, known as Hellish...