A grandfather comes to Ken's office with an emotionally disturbing case. Alienated by his family, the man wants to clear his name of allegations that he sexually molested his granddaughter. Ken must find out if he's an innocent man or a sexual predator.

The Lie Detective is a character-driven factual series that follows the work of independent Polygraph Examiner and self-professed truth seeker, Ken Donaldson, as he helps people from all walks of life in their quest for honesty, resolution and freedom from deception.