A Dangerous Collaboration by Deanna Raybourn

Victorian adventuress Veronica Speedwell is whisked off to a remote island off the tip of Cornwall when her natural historian colleague Stoker’s brother calls in a favor. On the pretext of wanting a companion to accompany him to Lord Malcolm Romilly’s house party, Tiberius persuades Veronica to pose as his fiancée–much to Stoker’s chagrin. But upon arriving, it becomes clear that the party is not as innocent as it had seemed. Every invited guest has a connection to Romilly’s wife, Rosamund, who disappeared on her wedding day three years ago, and a dramatic dinner proves she is very much on her husband’s mind.

As spectral figures, ghostly music, and mysterious threats begin to plague the partygoers, Veronica enlists Stoker’s help to discover the host’s true motivations. And as they investigate, it becomes clear that there are numerous mysteries surrounding the Romilly estate, and every person present has a motive to kill Rosamund…