Collaborators; Tyrol participates in a secret tribunal on Galactica that tries and convicts to death, in absentia, those accused of collaborating with the Cylons during the Occupation. Baltar faces a similar jury among the Cylons, who must decide whether he may stay with them. Torn; The Galactica encounters a Cylon Basestar devastated by a deadly virus. Feelings of rage lead Tigh and Starbuck to cause problems on Galactica between the New Caprica survivors and those who were with the fleet during the Occupation. Baltar tries to convince the Cylons of his value to them in an attempt to stay alive. A Measure of Salvation; a group of ill Cylons is brought to Galactica and Lee discovers a way to solve the Cylon problem forever - by destroying the whole race. Meanwhile, D'anna's acts to discover if Baltar is reliable will forge an unusual relationship. Hero; a figure from Adama's past returns to haunt him. His return raises questions about why the Cylons launched their initial attack against the Twelve Colonies.