Cancer-stricken President Laura Roslin lies near death in the Galactica's sickbay. Still lucid and in command, she orders that the pregnancy of the Cylon spy Sharon be terminated, after inexplicable properties are discovered in a fetal blood sample.
Dr. Gaius Baltar, who, as vice president, is poised to assume the presidency upon Roslin's death, protests that a half-human, half-Cylon child would make an ideal case study; the child's father, Lt. Karl "Helo" Agathon, also is outraged by Roslin's decision.
Admiral Adama is determined to carry out Roslin's final decree until Baltar discovers that the hybrid fetus's blood cells might possess fantastic healing properties.
Meanwhile, a secret group of Cylon sympathizers resorts to sabotage to demand that humanity sue for peace with the Cylons. Adama arrests their leader, Royan Jahee, but the group continues its violent revolt, bombing the tylium refinery ship, leaving the fleet short of fuel and vulnerable to enemy attack.
An even more ominous threat emerges when Baltar once again connects with Gina, a flesh-and-blood version of the Number Six who lives in his head. Gina has infiltrated the sympathizers' ranks, in an effort to promote the Cylon agenda.
Baltar realizes that President Roslin doesn't trust him to succeed her as president -and that she might, in fact, know of his affiliation with Caprica Six, who sabotaged the Colonial defenses. He discreetly arranges for a nuclear warhead to fall into the hands of Gina and the Cylon sympathizers, placing the entire fleet in mortal jeopardy.
