Proof of MurderMass Market Paperbound, 28 April 2020

In Lauren Elliott's fourth USA Today bestselling Beyond the Page Bookstore Mystery, bookshop owner Addie Greyborne must solve a locked-room murder in a supposedly haunted mansion to recover a priceless Sherlock Holmes original...

The seaside New England town of Greyborne Harbor is home to many grand estates, including the Queen Anne Victorian Addie inherited from her great aunt. Now one of those mansions is holding an estate sale, which is just what the bookshop owner needs to replenish her supply of rare editions--even if the house is rumored to be haunted. Assisting an overwhelmed insurance appraiser with the inventory, Addie discovers an 1887 magazine containing Arthur Conan Doyle's first Sherlock Holmes novel, A Study in Scarlet, which she estimates to be worth over one hundred and fifty thousand dollars.

But when Addie later finds the appraiser dead in the estate's private library, with the door bolted from the inside, and the priceless edition missing, it's a mystery worthy of the Great Detective himself. She's certain the death and the robbery are connected--but who, other than a ghost who can walk through walls, could have gotten in to do the deed? It's up to Addie to find the key to the crime--before she's the next one cornered by a killer...