Set during a twenty-four-hour period, this harrowing psychological thriller concerns Renate Simmons, an agoraphobic woman facing the breakup of her marriage. After enduring nine years with her hard-drinking psychiatrist husband David, she decides that she has to leave. Terrified of leaving the security of her home and of being on her own, Renate is seemingly trapped. Although David initially appears to agree that their marriage should end, Renate gradually becomes aware that he has been playing psychological and sadistic games with her, and does not intend to let her leave at all. The tension escalates as Renate begins to see how he has deliberately manipulated her psyche over the years in order to hold on to her and subsequently realises that she is in danger. She eventually gains the strength she needs to break free, but not before a final terrifying confrontation with her increasingly unhinged husband.