The Timeless Curse of Lord Dabney by Emilia Hartley

When Ellie Fitzgerald looks at herself in a mirror in Hargrove House, the estate her grandmother has left her, she’s looking at a version of herself from England’s Regency period. That version of herself invades her dreams, too, laughing confidently with friends instead of retiring shyly into libraries, and cavorting with a gorgeous but common young man named Matthew. The dream is so real, Ellie can still feel Matthew’s hands on her when she wakes.
She can’t shake the dream, especially when she finds a Matthew who looks exactly like the man in her dreams working at the local museum. She feels an instant connection, one he apparently shares, and together they discover a history of Ellies and Matthews loving each other all through their family’s histories.
They also find a more sinister figure recurring through the ages—Lord Dabney, a good-enough-looking man (though he’s no Matthew), who hounds the two lovers into early graves time and time again.
When a Lord James Dabney shows up at Hargrove House, determined to date Ellie, it feels like history could be repeating itself. Ellie refuses to let herself become the victim of an old curse, though. This time, she and Matthew mean to write the ending to their own story—if they can.