The Other Side of Midnight by Sidney Sheldon

In Paris...Washington...and a fabulous villa in Greece, an innocent American girl becomes a bewildered, horror-stricken pawn in a game of vengeance and betrayal.
She is Catherine Douglas, a woman caught in a web of four lives intertwined by passion as her handsome husband pursues an incredibly beautiful film star—and as Constantin Demeris, a legendary Greek tycoon, tightens the strands that control them all. Welcome to THE OTHER SIDE OF MIDNIGHT—and one of Sidney Sheldon's most dazzling and surprising novels of suspense.