The Summer Inn on Plum Island by Amy Rafferty

Dawn Vanderbilt craves a life of adventure. After her engagement was broken off two years ago, the screenplay writer has spent her time wasting away on Plum Island’s idyllic shores. It’s only when her niece comes to visit that excitement finally comes back into her life—along with a mystery she could have never predicted.

Liam Gains guards his scarred heart by focusing on his five-star hotel and his daughter, Lila. After a betrayal from his ex-wife, he has no interest in another romance.
But when one of his mother’s heirlooms disappears and a phantom thief is to blame, he’s thrown into a mystery alongside the aunt of his daughter’s new friend—a beautiful screenwriter named Dawn.
Together, the two work to track down the elusive phantom thief and dispel the specter haunting the Summer Inn. They navigate secret passages, decipher cryptic clues, and discover love in the darkness of shadows.