The Burning Glass — Lillian Stewart Carl

Ghostly rumors and the promise of a romantic getaway lure American historian turned journalist Jean Fairbairn to remote, crumbling Ferniebank Castle. Jean's beau, ex-DCI Alasdair Cameron, has been hired for security as renovations to turn the castle into a wellness spa are about to begin. But on the crumbling grounds, something sinister is afoot. An old caretaker is found dead in the dungeon, a harp played for Mary Queen of Scots has disappeared and a local man is missing.

Strange lights, looters, angry villagers and another dead body add intrigue both spectral and corporeal. And when the trail leads back to the new owner of the property -- Alasdair's ex-wife -- Jean suspects that something more disturbing than even murder awaits. Especially as she gets closer to the castle's long-buried secrets....