The Best Seasons of Threshold

Every season of Threshold ever, ranked from best to worst by thousands of votes from fans of the show. The best seasons of Threshold!

Threshold was a science fiction drama television series that first aired on CBS in September 2005. Produced by Brannon Braga, David S. Goyer and David Heyman, the series focuses on a secret government project investigating the first contact with an extraterrestrial species.