Charlie receives an enigmatic letter from her namesake aunt, her father's estranged sister, whom she's never met. Soon she's off to England. In the charming medieval Suffolk town of Bury St. Edmunds it isn’t only slightly eccentric Aunt Louisa’s beliefs in the occult or her spooky "haunted sites" tours that pique Charlie’s interest. When a friend of Louisa's is plagued by a series of pranks, Charlie and Louisa offer to find out what's behind them. But Charlie soon discovers that something sinister is brewing and she finds herself drawn into an investigation of crimes that are far too real.