On April 29, 2010, at 8:42, Mark waits in a cell at the Inmate Reception Center. Olivia and Charlie are on a beach watching the fireworks from the flashforward day celebration.
At Bryce's house, Nicole looks at his sketches of Keiko and then leaves in her car.
Keiko and Yuuka are at the airport, arguing about whether Keiko should stay. Yuuka insists that her daughter come home to Japan. Meanwhile, Bryce goes to the Immigration Center and bribes the guard to give him Keiko's phone number.
In Afghanistan, Aaron wonders how he could have seen her alive in his flashforward. Kahmir finds a pulse and works to revive the girl.
Demetri, Simon, and Janis arrive at a NLAP access point and Simon tells them that if they can get a scanner close to the security guard's access card, they can capture it on his cell phone and get inside. When Demetri balks, Janis insists and he agrees to help based on his trust in her. She starts to feel stomach pains from the struggle back at her apartment, and Demetri realizes something is wrong. He wants to get her to the hospital but Janis insists that they won't get a second chance and they need tog et Simon inside so he can find the evidence to identity the remaining conspirators. Demetri reluctantly agrees to continue with the plan.
Stan arrives at the Inmate Reception Center and gets Mark released.
As Stan drives, he blames himself for some of Mark's problems, admitting he was also obsessing about solving Mosaic. Stan receives a call informing him that bombs have been discovered at FBI Headquarters, and he heads there with Mark.
While Simon and Demetri sneak up to the gate, Janis approaches the guard and claims she's sick. However, Demetri is worried that she isn't faking. The guard calls an ambulance and Simon assures Demetri that she'll get proper treatment.
Lloyd and Dylan have their security detail contact Olivia's detail, and find her and Charlie at the beach. Despite Olivia's objections, Lloyd insists that they have to be together at her house at the moment of the flashforward so he can complete the equations.
As Bryce leaves the immigration center, he finds Nicole waiting for him. She apologizes for deceiving him, and Bryce admits that he loves Keiko. Nicole tells him to go.
At airport security, Yuuka realizes that her daughter has to find the man in her flashforward. She distracts the guards while Keiko escapes.
At FBI Headquarters, Stan insists that Mark stay in the car, but Mark believes the bombers are after something specific. Stan puts Aaron on the phone, and Mark's AA sponsor says that they all have to make their own choices. As Hellinger leaves, Mark goes to confront him and says he's going back to his office. Hellinger dismisses it as a fool's errand, but Mark figures that Hellinger is just trying to distract him. After Mark leaves, Hellinger secretly signals two of his men, disguised as bomb squad members, and they go inside the building.
Olivia and Lloyd go to the Benford home. As Charlie and Dylan run off, Lloyd says that they'll have to take the same positions they had in their flashforwards.
Demetri and Simon get to the accelerator access point and Simon apparently seals Demetri outside. The agent thinks it's a trick, until Simon gets the door open. To demonstrate his honesty, Simon gives Demetri the QED ring that he stole.
At FBI Headquarters, Vogel and his people confirm there are bombs throughout the building. Mark finds him and they both figure it's an attack on Mosaic... and that the conspirators will go after Lloyd. Vogel confirms that in his flashforward, he was at the Benford house, and telling another agent that Mark was dead. Mark goes in, but not before Vogel insists that they need Mark and Lloyd alive.
At the house, Charlie calls Olivia in to show her and Lloyd that Dylan is writing the formula on the bedroom mirror. Lloyd realizes that his son put it put it together from the equations he was looking at earlier that day, and that it ties everything together using the tachyon constant. Now Lloyd has to solve it.
Hellinger's infiltrators don masks and shoot a bomb squad team, and enter the building from the parking garage.
Janis arrives at the hospital and finds the ultrasound technician from her flashforward waiting for her.
In the bedroom, Olivia admits that the future happened as they saw it, despite her efforts to fight it. Lloyd wonders if everything they saw will happen, and they kiss.
Stan and Vreede run upstairs and hear gunshots. They split up to investigate.
In his office, Mark realizes that he's where he has to be.
Bryce discovers that there's a private party at the sushi restaurant, but Keiko's friend, Kitomi the waitress, lets him in. Meanwhile, Keiko is forced to abandon her taxi when it's caught in traffic and proceeds on foot.
Nicole is driving home when she swerves to avoid an oncoming car and goes off the road into a nearby lake.
As Simon tries to find the file, he offers a beer to Demetri and assures him that Janis will be okay. He then sends Lloyd a wave formula, an inside joke Lloyd used to sign all of his calls.
At 10 o'clock, Keiko runs through the streets. Bryce waits. Nicole sinks into the lake. Tracy looks up at her father. Janis looks at her child on the ultrasound monitor.
Lloyd gets the text from Simon, sees the wave formula, and realizes he has to make a call. He kisses Olivia and goes to call Mark. He tells him that the constant is the wave, and when he plugs it into the blueprint, it predicts the next Blackout sometime in the next two days.
Keiko arrives at the sushi restaurant and finds Bryce.
Nicole sees a man standing above her in the water.
The ultrasound technician tells Janis that the baby is fine, but it's a boy rather than a girl.
Olivia looks down and sees Lloyd in her living room, just like in her flashforward. Vreede and Stan hold off the gunmen, and Stan ducks into a restroom stall for cover.
Demetri is glad that they no longer have to worry about the future visions they've had, and Simon welcomes him to the future.
Mark examines the Mosaic board and realizes that Gabriel rearranged the strings. Comparing the strings to Gabriel's sketchbook, Mark discovers that the strings lead to words and letters, spelling out a phrase: April 29, 2010, 10:14. The time is 10:02.
Simon realizes that Hellinger cloned the mainframe and altered it as a decoy. He manages to access the original system and download the identities of the conspirators.
Charlie sees Vogel meeting with the FBI agent watching the house. Olivia sends her daughter back into the house, and then listens as Vogel tells the agent that Mark must be dead.
The gunmen move in on Mark's office. When his cell phone goes off, they open fire.
The man from Nicole's flashforward gets her onto the shore, and explains that in his flashforward he saw him rescuing her. He introduces himself as Ed.
At NLAP, Simon discovers that someone is activating the accelerator from off-site.
Mark ambushes the gunmen from a ventilator shaft, and then goes after the others.
Demetri orders Simon to stop and draws his gun. Simon insists that he won't let the conspirators turn him into a monster with the deaths of millions on his head, and goes to work to stop the startup sequence. Demetri considers, and then lowers his gun.
Stan hides in the stall and ambushes the gunman when he comes in.
Mark finds one of the bombs, with eight minutes remaining. He summons the elevator and uses it as a distraction to shoot and kill the remaining gunmen. Mark then calls Stan and informs him that the next Blackout is in a few minutes, and tells him to warn everyone he can. When Stan orders him out before the bombs go up, Mark ignores him as more gunmen move in.
As Stan alerts the world, Mark calls Olivia and tells her what's going to happen. He tells her that he loves her and Charlie, and Olivia assures him that they love him.
Demetri gets word of the alert, and tells Simon that this time, he's going to see the future. He gives the QED ring to Simon, who refuses to put it on.
The remaining gunmen open fire on Mark, Mark kills one of them and spots another bomb, with 39 seconds remaining. He runs for the nearest window and the helicopter outside.
Simon tells Demetri to brace himself when he's unable to stop the accelerator. The accelerator activates and a wave of energy sweeps across the world.
Bryce and Keiko are unconscious, holding hands.
Across the world, people have flashforwards of the year 2015.
At the hospital, Lita, wearing a QED ring, wheels out the unconscious Janis.
A kangaroo hops down the streets of L.A.
Charlie has a flashforward of herself as a teenager, telling someone they found Mark. She then wakes up,
FBI Headquarters blows up.