Previously on Battlestar Galactica Col. Tigh made the decision to network Galactica's computers temporarily to calculate FTL coordinates quicker while a Cylon virus infected the ship's systems.
Cally shoots and kills the first Sharon Valerii. Helo prevents Starbuck from shooting "Caprica" Sharon.
President Roslin tells members of the press that she has only a few months to live.
Chief Tyrol is examining an old Viper, looking down the hull toward the front. His actions mimic those of Sharon "Boomer" Valerii as she once caressed the captured Cylon Raider that Tyrol was trying to operate. Helo attempts to join the pilots' card game. Starbuck welcomes him but Racetrack, Hot Dog and the others ignore him. He decides not to stay. "So he's the Cylon lover," one of them says to Starbuck.
Tyrol remembers being with Sharon as he's examining the old Viper. He pulls out a tangle of wires and slaps a sticker on the ship that reads "UNSERVICEABLE SCRAP." The flightdeck crew is welcoming Cally back after her brief incarceration for shooting the first Sharon. Tyrol brushes her off.
Helo is sitting in Sharon's old Raptor drinking. Tyrol joins him.
Racetrack gives up on the card game. They've been playing with the same deck of cards for so long that she recognizes cards by their bent edges. "I just want it to end--the bad food, the endless rotations, pretending that a card game is the highlight of our day." She brushes her jacket right over Starbuck's face. Starbuck gets up to find Helo. Racetrack comments "Good idea. Maybe that Cylon whore taught him a few tricks." Starbuck turns around and slams Racetrack into the card table, face first.
Tyrol becomes agitated with Helo. He had planned to marry Sharon after they left the service. He tells Helo that he's thankful for him. "That freak in her belly could have been mine." Helo pushes him backwards off the Raptor wing. Enraged, Tyrol attacks Helo. Helo tries to end it. Tyrol screams "You don't get to call it!" He throws Helo to the ground and picks up a large wrench. He gets a hold of his senses and drops it. He slumps to the ground. "I don't know why I'm mad at you. My Sharon's dead. That thing--in the brig--that isn't Sharon."
Dualla hears a loud noise on her headset. Gaeta says that the ship is now transmitting what could be a locator signal. Dualla's console shorts out and she is knocked backward by a power surge. We see a large Cylon attack force. . . .
The opening titles tell us there are 47,853 remaining survivors.
Tigh barks at Gaeta to find out what happened to the computers and Dualla's console. "I don't care if you have to go through this line by line!" Gaeta objects, saying he's already running several diagnostic programs. Tigh doesn't want excuses. "It's not an excuse, sir; it's a FRAKKING FACT!" Adama calmly tells Gaeta to pull himself together. Tigh admits to Adama that the crew needs a rest. Adama agrees. They've been on the run too long. "The only thing we can look forward to is this."
Apollo is upset with Tyrol that the Viper has been condemned. Tyrol details all the major problems with the ship. He can't work his crew to death. Apollo tells him "Nobody's expecting any miracles." Chief Tyrol says to himself "Maybe that's the problem." He sits up that night deep in thought.
We see him in working on a frame with a metal grinder in the ship's bay. His crew walks up. "We are gonna build a new fighter." They express their disbelief. The Chief tells them that all the work would be done on their free time. He can't convince them so he orders them to go back to their regular duties.
Doc Cottle gives Roslin her medical report. Her hands begin shaking. "How much time do I have?" "Weeks. A month at the outside." "Will I be able to work?" she asks. Yes. "Unless the cancer goes to your brain."
Apollo, Starbuck and Hot Dog are taking target practice at the firing range. Apollo's target has a picture of Boomer on it, which he is shooting at furiously. In the background, the oxygen gauge begins dropping toward zero. Apollo is skeptical about Tyrol's new Viper. Starbuck starts laughing. She says she'll fly it. "Why?" Apollo demands. "Because, while everyone else is standing around whining, the Chief is doing something positive." Hot Dog walks to the door but collapses. Apollo grows weak but slams his body into the door trying to open it. Starbuck is giggling hysterically. Apollo realizes there is no oxygen. Starbuck grabs a pistol and shoots at the door, shoots at the lock, shoots at the window. Nothing--and no more bullets. Apollo reaches up to the table and grabs a bullet. He helps Starbuck load the gun. Running out of air, Starbuck manages to lift the gun and shoot . . . . The window explodes along with the entire door.
Gaeta discovers that the environmental computer bled out the air from the room. Baltar tells Tigh that it's a Cylon logic bomb, a heuristic computer virus, very difficult to combat. He tells Adama it was left over from the computer network that Tigh set up the day Adama was shot. Adama says he's lucky. "I have an expert on board. Tell Helo to run this past our prisoner."
Chief Tyrol is trying to attach a wing to the Viper by himself. He's struggling with it until two members of his team decide to help him out. Adama looks on from above, pleased at their activity.
Tigh refers to the ship as an "imaginary fighter," a "pipedream." Adama says "This project, it's given them something."
Dualla is practicing hand-to-hand combat with Apollo. As part of the training, she flips Apollo onto the mat and knocks away the plastic knife he's holding. Then she slips down until her face is inches from his. She looks into his eyes, until Billy knocks at the door. She jumps up, happy to see him.
Helo asks Sharon if she remembers the Chief. Is she still in love with him? "You're the father of my child. You're first in my heart. Nothing's going to change that." "OK." He holds up the computer printout from the CIC. Sharon scans it through the window. She recoils in horror. It's a Cylon virus. It's been learning the ship's systems, testing them. The Cylons are going to attack soon. She has to see Adama. "I'm a mistake. They're gonna kill us all."
Adama meets Sharon. Meanwhile, Apollo inspects the new Viper. He says the cockpit is too far back. They will have CG (center of gravity) problems when maneuvering. "She's built for speed," Starbuck explains. Dee is also there, underneath the ship fixing the communications wiring. Tigh looks in on the "class project." He asks Apollo if he is working on it too. He walks in on Tyrol who is making alcohol to trade for parts. Tyrol claims it is solvent for cleaning parts but Tigh knows a still when he sees one. "We both know that piece of crap out there's never gonna fly!" Tigh asks why he's doing this. Tyrol appears crushed. "That ship--that's all I have left . . . ." Tigh walks to the door but turns around. He remembers that he promised a favor to the captain of one of the civilian ships. He is supposed to take some DDG62 engines off his hands. Tyrol is surprised, and relieved. As the price of the engines, Tigh picks up a jar of liquor and walks out without saying a word.
Roslin is packing up her belongings from Adama's quarters. She returns the book that she had asked to borrow a long time ago. Adama reminds her "This was a gift" and that she was meant to keep it. She says she's had it too long. Adama tells her about the Cylon virus, which he has just been informed is a prelude to an all-out attack by the Cylons.
Gaeta wants to erase the hard drives, restart the ship's computers and load information from the backup files. Tigh is skeptical but Baltar pointedly asks him whether he wants them all to live or not. [Surprisingly, Number Six is not present here at Baltar's side, whispering in his ear.] Tigh wants to plot an FTL jump. They can't, Gaeta explains. The computers are corrupted and they could wind up in the middle of a star.
Adama wants Roslin's advice. Should he trust Sharon, the Cylon, to help them? "This is not the one who shot me." Roslin thinks that Adama's judgment has been clouded by his history with the Sharon model but she adds, "We created them. There's always a chance we might find a common ground."
Sharon is led in chains and a neck restraint pole into the CIC. She says "We need to work quickly. We're on borrowed time." Adama agrees to unchain her. Sharon asks Dee if she still carries her father's pocketknife. Adama tells her it's OK to give it to Sharon. Sharon also asks for a fiber-optic com link to the mainframe computer.
Multiple DRADIS contacts. Cylon Raiders. Launch Alert Vipers. A large Cylon attack fleet is approaching in formation. Sharon slices open her left hand with the knife. "The Raiders are gonna send a signal to activate the virus." Gaeta needs to be on standby, ready to wipe the hard drives. "Sometimes you gotta roll the hard six. Right Commander," Sharon exclaims.
"What the hell is she doing?" Tigh bellows. Sharon tells Gaeta to wipe the hard drives. Adama gives the go-ahead. The entire Viper fleet approaches the Cylon Raiders, which are arranged in rows of interlocking diamond-shaped formations.
Sharon inserts the fiber-optic cable into her hand, threading it up her left forearm. The Raiders continue their approach. Galactica's computers are still down. "We're looking at a goddamn bloodbath! She set us up!" Tigh screams. Adama asks for the guard's sidearm. He presses it up against Sharon's head.
Her eyes are rolling up into her head while she holds the cable in her forearm. "Do it!" Tigh shouts. Shoot her! What are you waiting for? Sharon slumps to the ground. "This." She pulls the cable out of her arm. All the Cylon ships lose power and begin to drift out of control. Adama realizes that the Cylons sent them a virus and Sharon sent the virus back. "Kill the bastards!" commands Tigh. "This is payback" Apollo says over the radio. The Vipers begin targeting all of the Raiders, tearing through their armor and ripping them to shreds. The Cylon ships bleed and reveal their organic innards. [Adama chooses not to salvage any of the disabled Cylon ships for study or future missions.]
Adama seems to smile briefly at Sharon. He recovers and shouts an order to the guards. "Take this thing back to its cell."
Sometime later, the Chief is working on the new Viper again. Cally helps him push some wiring into place. "Nice to be small, huh?" Tyrol observes. He seems to have accepted her back and she joins the construction team. Starbuck looks at the Viper. They are so close! She is looking for spare metal to use for the skin. "Who says you need metal?" It's Helo.
The new ship looks sleek, outfitted in black--carbon composite. "Hard as hell to see on DRADIS," Apollo says. Starbuck gets into the pilot seat for the inaugural flight. She shoots out of the launch tube. The Blackbird spirals out of control. Apollo, trailing in a regular Viper, tells her to stop showing off. Starbuck isn't. She is struggling with the ship's handling. Finally--she straightens out the ship. Next, a flash of light--and the Blackbird--is gone! "Starbuck! Starbuck!" Apollo calls on the radio. Where are you? He pleads and then becomes desperate. The construction crew, the CIC staff, everyone awaits with bated breath. Where are you Starbuck? No DRADIS contact. The ship floats up silently in front of Apollo's Viper. Starbuck turns on her helmet lights. "Of course you lost contact. It's a damn stealth ship. Remember?"
Roslin arrives for the dedication ceremony. The construction team signs the Blackbird in silver ink. Roslin says "This is more than a ship. This is an act of faith." She adds "We will get through this, all of this, together." The Chief tells her they wanted it to be a surprise as he slides the black banner off the nose of the ship. It reads "Laura," named in honor of the President. She is genuinely moved by the gesture. Adama hands a champagne bottle to her. She looks at it and suddenly raises it above her head as though she were striking the ship. Tyrol reaches out in front of her. "Kidding," she says. Adama exchanges a brief glance with Tigh over it. Roslin opens the bottle with a pop. She sprinkles some champagne on the Blackbird with her hand.
Racetrack walks up to Helo. "Hell of an idea using carbon composites," she says as she offers her hand. Helo slowly accepts. The other pilots also greet Helo and welcome him back.
Roslin tells Adama, "None of this would have been possible if you hadn't trusted the Cylon." Adama discovered the common ground. "We both wanted to live."
Chief Tyrol walks up to Sharon's cell. Sharon, wearing a cotton warmup jacket, sweatpants and no shoes, sits up from her table and walks to the locked door. She looks at Chief and picks up the phone. The Chief looks at her and brings the other phone to his ear. (fade to black)