The Hustler

Each episode of The Hustler follows five contestants as they collaborate to answer a series of trivia questions, with the goal of building a collective prize pot that increases with each correct answer. The catch? One of the five contestants, the Hustler, already knows the answers but must keep their identity a secret in order to have a shot at winning the grand prize. Throughout each episode, two contestants are anonymously eliminated by the Hustler, leaving three remaining contestants – the Hustler and two others, who must collectively decide who they think the Hustler is. If they are right, they share the prize pot. If the two contestants are wrong, the Hustler goes home with the full cash reward.
-Source: TVMaze