Sharon helps the Resistance on New Caprica as Adama leads Galactica on a dangerous rescue operation. Tyrol races to save Cally from the execution squad. Meanwhile Anders uncovers treachery among the humans. Number Three meets the Oracle Selloi after having strange dreams about the temple.

Tigh must decide the fate of his wife Ellen after the assistance she rendered to the Cylons. Lee struggles with his assignment to protect the civilian fleet on its journey toward Earth while Adama returns to New Caprica with just the Galactica. The Resistance coordinates an attack on the Cylons just as Galactica arrives. As the Cylons begin to lose control, Number Three vows to put a final end to the New Caprican experiment.

The untold story of Lee Adama's first mission as commander of the battlestar Pegasus begins as Lee asks Kendra Shaw to be his executive officer. Kendra—who's tough but troubled—was considered an exemplary officer by the Pegasus's original commander, the late Admiral Helena Cain.

Admiral William Adama assigns the Pegasus to find a Raptor that vanished during a scientific-research mission. At the Raptor's last known location, an armada of antiquated Cylon Raiders piloted by Centurions attacks the Pegasus. The captive Sharon identifies the old-fashioned machines as "guardians," a particular group of Cylons who experimented on humans during the first Cylon War.