In the new season, our polygraph expert Dr. Carl Letterman (Tim Roth) continues to use his amazing ability to see through a series of superb or lame lies, but even such a divine character has people and things that cannot be handled. In order to fight for custody of his daughter, he took the fate of the company alone, and for this reason, he had to take on any case that could bring money with his teammates. But even so, his relationship with his daughter and even his ex-wife is still hot and cold. At the same time, Gillian Foster (Kelli Williams) also walked out of a failed marriage and began an independent life, and her relationship with Letterman was close and ambiguous. Eli Locker (played by Brendan Hines) is increasingly working alone with Leah Torres (Monica Raymund), and the relationship between the two, who have always been bickering, is slowly getting closer, and in the face of Letterman, who often hits him, Locker also has an idea.