Although only lightly known as an author of horror stories, Barry Pain departs from his typical themes with 'An Exchange of Souls'. In this novel, respected doctor Daniel Myas is a scientist who has developed a machine which allows for the exchange of his 'personality' with that of another. However when his attempt at 'exchanging souls' occurs with an individual very close to him, only a form of horror can be the result, and the reader is led down a path of deterioration and fear. Undoubtedly this novel, published in 1911, influenced H.P. Lovecraft’s tale of personality exchange in 'The Thing on the Doorstep', published in 1937. Pain's development of the theme of immortality by use of scientific methods proves quite difficult, and at the same time quite intriguing. What are the potential results when 'souls' are exchanged, particularly with those of the opposite sex?