After the rebel Cylon baseship rejoins the human fleet, D'Anna sparks a standoff by seizing Roslin, Baltar, and their entourage as hostages. She announces that she will hold these hostages aboard the baseship until the four Cylons hidden in the human fleet return safely to their own people. Tory Foster defects immediately, but the other hidden Cylons keep quiet.
Back in command aboard the Galactica, William Adama consults with Lee, who is still acting as President in Roslin's absence. According to prophecy, the hidden Cylons will reveal the route to Earth, and Roslin has secretly ordered Adama to destroy the baseship-- even with her aboard-- if that's the only way keep the Cylons from claiming Earth for themselves. The human leaders thus face two grim alternatives: if the hidden Cylons defect, the humans must destroy the baseship to prevent the Cylons from finding Earth, but if the hidden Cylons stay underground, the hostages will suffer. As if to prove this point, D'Anna executes a hostage and threatens to kill more unless the three remaining Cylons join her. In response, Lee orders Kara Thrace to plan a hostage rescue mission.
As preparations for the dangerous mission get underway, a Cylon musical signal summons Tigh, Tyrol and Anders to the mysterious Viper that Kara flew back to the fleet after her mystical journey to Earth. Intrigued, Tyrol and Anders ask Kara to help them examine the Viper. Tigh, meanwhile, resolves to stop the impending bloodshed at any cost: he finally tells Adama that he is a Cylon. Adama breaks down in fury and grief, incapacitated by this unimaginable betrayal. Lee takes charge and orders Tigh marched to an airlock to await execution. There, Tigh reveals the identities of Tyrol and Anders, who are arrested before Kara's horrified eyes. As Anders is dragged away, he begs his wife to study the Viper. Stunned, she retreats into its cockpit and starts flipping switches.
Lee radios D'Anna that if she doesn't release the hostages, he will execute Tigh, Tyrol and Anders. His resolve is steely despite the painful shock of seeing such well-known faces awaiting death at his hands. D'Anna similarly refuses to back down, targeting the civilian ships with the baseship's weapons. If the three Cylons die, so will thousands of humans.
Seconds before an apocalyptic battle erupts, Kara discovers that her Viper is receiving a locator signal that no other ship in the fleet can detect. If it's from Earth, then Anders and Tyrol have fulfilled the prophecy by giving her a crucial clue to the planet's location. Faced with this awesome possibility, Lee and D'Anna hesitantly make peace. Lee offers amnesty to Tigh, Tyrol, Anders and Foster, and D'Anna releases her hostages. Then, with Lee and Roslin's help, William Adama pulls himself together and orders preparations for a jump.
The fleet and their Cylon allies follow the signal to Earth. What awaits them at the end of their long journey, however, may break their hearts.
BRADLEY THOMPSON and DAVID WEDDLE
Ascension, a three night event, premieres on December 15 at 9/8c
Get a sneak peek at the next episode of Z Nation, airing Friday at 10/9c on Syfy
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