Forensic psychiatrist Dr Claire Roget finds it impossible to refuse when she receives a desperate phone call from an old acquaintance, obstetrician Charles Tissot. One of his patients, Heather Krimble, alleges that Tissot seduced her at a party and that he is the father of her unborn child. His career on the line, Charles begs Claire to expose Heather's fragile mental state and discredit her wild claims. With a history of making similar false allegations, her two previous babies having suffered unexplained cot deaths, Heather's accusations would appear to be nothing more than the result of a damaged mind. But as Claire delves further, it becomes clear that Charles hasn't been telling her the whole truth.