8. Firefly
20th Century Fox
Episode: Objects in Space (2002) Joss Whedon's cowboys-in-space sci-fi series Firefly is perhaps the most infamous of those series that have been cancelled after a single season, despite wowing critics and fans alike. In this respect then, Firefly is more of a show known for its unrealised potential than unanswered questions but the episode that turned out to be the final one produced did leave some open threads. One of the most intriguing is that of the enigmatic Shepherd Book, a deeply religious Christian who acts as the moral compass for the crew of the 'Firefly' class spaceship Serenity. However, throughout the series he demonstrates abilities and knowledge more than a little unusual for a religious man - even in hundreds of years in the future - including criminals, weaponry and space travel. In the finale itself, bounty hunter Jubal Early opens up another can of worms when he assaults Book, saying 'that ain't no shepherd.' Further suggesting that Mr Book might not be such a squeaky clean servant of the Good Book after all... In the end, we never find out the real truth behind the seemingly paradoxical Shepherd Book - not even the follow-up film Serenity shed any light. Thanks, Whedon, you couldn't help the cancellation of the show but you could have given us some peace and serenity on that matter.