S04E08: 'Sine Qua Non'

Natalie is taken to the medical centre and treated by Doc Cottam, but she dies. Admiral Adama berates Sharon for killing Natalie and fears that Roslin may be killed by the Cylons as revenge.

In Roslin's absence, the hunt for a new President is on, although Tom Zarek is ruled out because Adama won't accept him. Apollo begins the hunt and visits Romo Lampkin, the man who represented Baltar in his court case.

Tigh visits Number Six, who asks him if he loves her just as he has a vision of ex-wife Ellen. Adama makes Galactica do a jump and discovers that the Hub has been destroyed, although there is no sign of the Basestar or Roslin.

Adama finds out that Number Six is pregnant and immediately confronts Tigh, who is stunned and lays into Adama for his obsession with Roslin. The pair trade punches and Adama's treasured model boat is smashed in the process.

Lampkin visits Adama and encourages him to consider Tom Zarek as President. Later, Lampkin tells Lee that he is the right candidate for the Presidency - and he takes over from Roslin and gives Romo a dog to replace his dead cat.

Adama opts to hand over command to Tigh as he wishes to search for Roslin in a Raptor. His son, now President, fails to change his mind.