And so The Mystery is solved. Those of you who read my advance review of this week's season premiere of Battlestar Galactica ("Sometimes a Great Notion") know that I was prohibited by the network from discussing any major plot points from the current installment, which kicks off the final batch of episodes of BSG before this gripping and intelligent series takes its final flight among the stars. But now that the episode has aired (likely to the sound of a collective gasp from fans around the country), we can get down to the business of discussing the head-trippy revelations that this week's episode of BSG , written by David Weddle and Bradley Thompson, unearthed. Ellen. I'm sure everyone here wants to talk about the fact that we finally learned that the Final Cylon was in fact Ellen Tigh, who was killed by her husband Saul back on New Caprica... for collaborating with the Cylons. Tigh, of course, later learned that he was a Cylon and he poisoned Ellen after she