Necroscope

Harry Keogh has always been able to talk to the dead, and as a boy in northern England he grows up quietly conversing with the departed, learning secrets no living person can access. That gift turns dangerous once he sets out to understand how his mother really died at the hands of his Soviet-agent stepfather, a search that draws the attention of both British and Soviet psychic-intelligence agencies who want to weaponize what Harry can do. What he uncovers instead is a far older and hungrier evil, one that has been feeding on the living from the shadows for centuries. The book that opens Brian Lumley's long-running Necroscope series.