The Vanishing Bride by Mimi Gunn

Charlotte Townsend had tasted love before.
The price had been too high to bear.

A scandalous secret drove her into hiding on a remote family estate. True safety lay in being forgotten. When a gravely wounded man arrives on horseback, her peace is shattered. She must decide if the one who once held her heart can keep her secret safe.
Lord Peregrine Spencer never expected the woman from his fevered dreams to appear before him. Sent by his brother to expose nefarious dealings at the Spencer estate, his investigation ends with a bullet to the chest. A love-scorned widower, his horse leads him to a place from his past. Is he seeing a ghost—or the woman once thought lost? Could this tragedy reunite him with his heart’s desire?
When long hidden secrets necessitate a marriage of convenience, Charlotte must choose between guarding her heart or trusting her new husband. To secure their happiness, Peregrine must unmask his would-be killer before losing his love forever.

This is book one in the Lost Loves series, spicy regency romantic suspense books with a guaranteed happily ever after.