There is no need for a lie detector, no conclusive evidence, or even a voice. In most cases, a person who lies or not can be judged by a slight change in facial expression. This is the superb skill of Dr. Carl Letterman (Tim Roth Tim Russell). Dr. Letterman works for a private organization that specializes in the study of microexpressions and is absolutely authoritative in determining lies. When the FBI, the police or the private sector are faced with outstanding issues, it is a good time for Dr Letterman and his team to do their best. With their rich experience and cautious work style, they debunk one lie after another and restore the truth. In front of them, any liar has nowhere to hide. This film is based on a true story.