 He built up a volume of correspondence with paranormal investigator Harry Price and after Price's death, Paul Tabori would become literary executor of the Harry Price Estate, with whom Underwood worked with to publish all his research into Borley.Price had written and published two books about Borley- "The Most Haunted House in England" (1940), and "The End of Borley Rectory" (1946), from which Underwood 'compile[d] a really comprehensive index of the combined volumes'.