An exchange of souls

"Doctor Daniel Myas is carrying out experiments in order to transfer human souls. When the doctor dies suddenly from an overdose of drugs, his special apparatus transfers him to the body of his fiancee, Alice. The girl herself dies shortly afterwards in a train crash and the ghosts of the two endavour to resolve their endless future."- - Description by Peter Haining, in "A Century of Ghost Novels 1900 - 2000" (Appendix to his book, The Mammoth Book of Modern Ghost Stories)