Based on the show of the same name this is clue on speed. Each player plays the FBI and an x-file. The object of the game is to discover your opponents x-file. Each x-file has 4 traits with six subtraits within each trait. During the game you use your agents to investigate sites. If you do this successfully you can ask one yes or no question. This is usually in the form "Does your x-file have the ______ trait?". While it is your turn you can play extra agents, equipment, allies, events and sites to investigate. Your opponent can play Adversaries and events. If after every one has played the cards they want you check the site card for its requirements then check you agents, if any are left, for their skills. If you met the sites requirements you have investigated the site.
There is also an advanced game with its own rulebook.