1. Tigh (and the other three of the final five) finally reveal themselves to the Adamas and the Cylons and all concerned. Admiral Adama correctly doesn't believe it at first, asking Tigh how he lost his hair, and how he could have gone back 30 years with Adama, without revealing that he was a Cylon. Tigh has no good answer, other than that once upon a time, no one knew about the skin-jobs, and now there apparently are three rather than two kinds of Cylons (toasters, skinjobs, and skinjobs who don't know they are Cylons until some Bob Dylan music triggers them).
2. D'Anna lets us know that the 5th of the final five is not in the human fleet. Does this mean he or she is with the Cylon fleet (Baltar, Laura, etc) or somewhere else entirely?
3. A great showdown between the Cylons and the humans, in which Apollo really shows his stuff.
4. But both decide to go to Earth, the coordinates of which are now apparently revealed, rather than annihilate each other ...
But ... the Earth they find is in ruins...
Not the most original twist in the universe, but a good enough springboard for the final parts of the final season ... Why is Earth in ruins - i.e., who ruined it?
Can it be repaired?
And, how does that ruined Earth relate to ours - the one in which we are currently enjoying Battlestar Galactica?
See also ...
Battlestar Galactica's Back and Bristling! ... 4.2 Mysteries and Satisfactions ... 4.3: Deaths, Lessons, Questions ... 4.4 A Little More about Cylons ... 4.5 Mutiny on the Demetrius ... 4.6 Cylon on Cylon ... 4.9 Finally, Bill and Laura
"jumping with ideas" - Denver Post