Debbie and Jo (both portrayed by Theresa Russell) are identical twins. Jo is killed in a car accident, and her husband, Cardiff physician Sam Crawford (Jonathan Pryce) is grieving for her. Despite this, Debbie starts to act increasingly like Jo for Sam to overcome his grief. Sam meets with, and is drawn to, Chloe (Catherine Neilson), his wife's former colleague. Meanwhile, Debbie, whose fertility problems seems exacerbated by a post-viral weakness, insists that she still feels Jo's presence. Mysterious circumstances lead Sam to suspect that Jo's death wasn't an accident at all.
