Sandy Bay, Hobart. January 27, 2009. 55-year-old mother of two Sue Neill-Fraser is woken by a call from the police - her yacht is sinking out in the bay. Sue's partner Bob Chappell who was sleeping on board has disappeared. The boat has been sabotaged, blood spatters the cabin stairs, a knife lies on the floor... Bob is never seen again - alive or dead. Sue soon becomes a suspect in Bob's murder investigation. During interviews with detectives she is caught in a string of lies. Seven months later, Detectives arrest Sue charging her with murder. Sue strongly maintains her innocence. While evidence is circumstantial and there is no body, the case against her is strong enough to go to court. After a high-profile murder trial that splits the tight Hobart community, Sue is found guilty. In October 2010 she is sentenced to 26 years in prison. But this case is far from closed... a band of supporters refuse to accept that Sue Neill-Fraser is a killer and they begin their own investigation, much of it filmed as it happens. In the tradition of The Jinx and Making a Murderer comes Undercurrent - a gripping Australian true crime series; an active unfolding investigation involving underworld sources and the chase for a key piece of physical evidence that could free Sue from prison, and finally unlock the shocking true story of what happened to Bob Chappell that night.