Swim Deep by Beth Kery

She’d made a career out of studying light, but now she’s entered a seductive, dangerous world of shadow and lies . . .
Anna Solas, poor artist working two jobs, is swept away by Evan Halifax, his charm and his good looks, and marries too quickly for her family’s comfort. Evan takes Anna to his stunning lakeside mansion the North Twin on the Les Jumeaux estate, where she discovers he lived with his first wife Elizabeth until her disappearance and presumed death. He says they can live anywhere Anna wants to, but his explanations unravel bit by bit. Anna is increasingly uneasy, wondering what really went on in the decadent home theatre, who is watching her from the South Twin—the matching home on Lake Tahoe’s shore, and the identity of the nightmare woman who appears to her at night, whispering a message she dreads hearing. She becomes determined to uncover the truth behind Elizabeth’s life in order to save her own sanity.