On a winter night on a remote road in Nebraska, Mark Schluter's truck turns over in a near fatal accident. His sister, Karin, returns reluctantly to their home town to look after him. But when he finally awakes from his coma, Mark believes that Karin - who looks, acts and sounds just like his sister - is really an identical imposter. Shattered by her brother's refusal to recognise her, Karin contacts Dr Gerald Weber, famous for his case studies describing the infinitely bizarre worlds of brain d...