Colin, a successful businessman in the real estate and stock markets in southern England, has his life firmly under control. But one day, his older sister Abigail – who is in serious trouble following the death of her much older, aristocratic, and heavily indebted husband – unexpectedly shows up at his doorstep after twenty years and asks for his help. Out of loyalty, he takes her in. To secure her position, she stops at nothing, not even seducing her own brother. Her desire to have him all to herself becomes an obsession. And Colin increasingly succumbs to the spell of this femme fatale, who is as seductive as she is cunning. But the relationship, which violates social taboos, cannot remain unnoticed by the outside world forever and has no future…