The Poison Pen A Scottish Bookshop Mystery

The Poison Pen, the ninth installment in the Scottish Bookshop series by Paige Shelton, set in a specialty bookstore in Edinburgh called The Cracked Spine.
Edinburgh is mourning recent the death of Queen Elizabeth II when Bookseller Delaney Nichols's boss comes to her with a most unusual assignment. An old friend of his, living in an estate in the village of Roslin, has found what could be a priceless relic on her property, and Delaney is tasked with investigating. Could Jolie possibly have an item of breathtaking Scottish historical significance in her possession? But when Delaney arrives at Jolie's estate, she is greeted by a legal team with a vested interest in the property. Jolie manages to remove the interlopers, but as they're examining the priceless item, they hear a scream, and meet a much less welcome discovery: a body.
As Delaney digs deeper, she discovers Jolie's own fascinating history. Jolie's mother had long claimed that her daughter was the rightful heir to the throne, not Elizabeth II, because of an affair she claimed to have with King Edward VIII. The only evidence, however, is in the form of a purported journal that one of Edward's secretaries kept. The puzzles become more confusing when a connection is uncovered between this far-fetched story and the murdered man. Delaney will have to read between the lines to put together the pieces...or become history herself.