What will it take to tell the truth when your life depends on a lie? A year ago, a father and his fiancée were brutally stabbed in their opulent London townhouse, sparking the most high-profile murder investigation in recent history. Blood spatter expert Doctor Claudia O'Sheil's evidence put the killer behind bars - or so everyone believes. Since the trial, Claudia's learned a horrific truth - her evidence and her testimony were wrong. And someone she knows made sure of it. Now, as she takes the stage to give a career-defining speech before London's elite, Claudia faces a devastating choice. Protect her children and her livelihood with her continued complicity or blow the whole conspiracy apart and reveal the truth - not only is the real murderer still out there, they're in the audience. As Claudia steps toward the microphone, she revisits that fateful night. What really happened?