The world's leading deception researcher, Dr. Cal Lightman, studies facial expression, body language and tone of voice to determine when a person is lying and why, which helps law enforcement and government agencies uncover the truth. But his skills also make it easier for him to deceive others.

Alec Mercer is a world-renowned professor of behavioral psychology with a unique insight into human nature who lends his expertise to an array of high-stakes cases involving governments, corporations and law enforcement. However, he meets his match in a female domestic terror suspect who turns his world upside down.