When you have a great series why spoil it with a weak, humourless, overly dark last season? The last season was a very weak storyline stretched out into 9 episodes. The earlier seasons had bits of humour sprinkled throughout, they were light and plenty of action that we like to see. It was like the sci-fi version of the Goonies. I would have given the whole franchise a 10 rating but the whole thing about the last season has let it down.