In the last film of the Lie Lab series, Kathy O'Beirne alleges that she was physically abused by her father; raped at the age of 6 by an older boy; raped again at age 8, this time by a Catholic priest; and raped for a third time when she was 13, by a volunteer worker. Kathy's memoir tells the tale of a horrifically abused child and has become a best-selling book. Her brothers and sisters refute her claims completely, going as far as to suggest that Kathy's book be sold as fiction, instead of autobiography. Who is telling the truth? Professor Sean Spence, who has pioneered the use of functional magnetic resonance imaging to detect when someone is lying, scans Kathy and her brother while they respond to each other's allegations. Can Kathy back up the claims she made in her autobiography? Will her brother's testimony reveal that she is lying?