i presume you watched all of S1 of BSG so i'l continue
Season2 starts off with the arrow bringing back to the human fleet along with the pregnant cylon/human woman i cant remember the name off who's clone shot the captain of galatica, shes arrested when they get back. later on they find a 2nd battlestar with a admiral i think whos wants to take over the whole fleet, she has a cylon who is in the docter guys head (the blond one), shes been raped a couple of times, doctor goes to help her, he lets her escape, she shoots evil captain of the higher tech BS, she then "disappears". any way galatica's captains son takes over the higher tech BS. i think i'm missing a bit here but any way. cylons send another cylon/human to say they want peace. humans settle on planet shielded. oooooooooh just before this the number 6 that wasnt in the docters head who was on the newer BStar sets up a terroist thing, the docter gives her a nuke, she explodes some random ship, the cylons pick this up from light years away (thats why of the huge time gap between peace and them reappearing) they take over the planet the humans have settled on, also the docter is the president (they have a vote when finding the new planet ) hes like all drunk,pimping and stuff. cylons appear, season 2 ends, also the 2BStars jump to hyperspace as the mass of cylons appear. deffinatly worth watching