Airdate: Wednesday.25.May.2005
Before the Flood

Jack, Irina, Nadia, Vaughn and Sydney land in the city of Sovogda. They
walk through a deserted street littered with corpses and burning cars. As
they wait for the Department of Special Research team, they speak to
Marshall and Weiss, who report that Director Chase is trying to convince
the Russians to call off the air strike.

At APO, Marshall and Weiss use the Blackwell Index to blackmail a Russian
minister into giving them the access code to a Russian satellite. They soon
discover that Elena is uplinking to the Russian network.

Syd follows a DSR signal, which leads to a severed arm. Suddenly, a CIA
agent named Brodien emerges from the shadows and tells them that his DSR
team was ambushed by the infected mob, which has left thousands dead. He
reminds them that the Rambaldi device is broadcasting a subaudible
frequency that physiologically alters people who drink the water. The
symptoms, he says, are irreversible.

He also says the epicenter is located over the Oransky building, and that
while he has taken out the city's power grid, the device is still running.
Irina suggests that it has been modified to run using an internal energy
source. They decide to take the subway, as it is the quickest way to the
building.

Elena learns of the APO team's arrival. When Sloane volunteers to lead the
assault team, Elena tells him to bring Nadia back and give her the option
to join them.

As the APO team approaches the subway tunnel, an infected man impales
Brodien with a rod. As Jack, Vaughn and Irina try to start the train's
emergency battery system, Syd and Nadia go inside the train's switching
room to force the train to stop at the Oransky building. Irina urges Vaughn
to tell Syd "the truth." Syd tells Nadia that Vaughn asked her to marry
him. Nadia and Sydney split up to manually adjust the switches.

Sydney returns to the train first while Nadia, down the tracks, flips the
switch. The train rolls down the tracks as a mob chases Nadia. Jack refuses
to stop the train because if he does, it won't start again. Sydney
stretches to pull Nadia to the train but she's tackled by an infected
madman. Irina tells Syd that Nadia is still alive.

Sloane kills Elena's men and waits at the station. He tells them that Elena
has primed the world's drinking water. As Syd voices her suspicions, Sloane
says he allied himself with Elena to put an end to this himself, but Elena
built in a security device that Sloane couldn't crack. Jack punches Sloane
and takes control of the team.

Marshall reports that Elena is going to use the Russian satellite to
distribute the Rambaldi frequency worldwide. Once it goes online, the
Rambaldi signal will be broadcast and everyone will be infected. Irina says
they need to shut down the device from the roof of the building.

Jack tells Sloane to take them to Elena. Sloane cautions that once they
disable the device, the toxins will dissipate in the atmosphere and the
person who disarms it will only have a few seconds to run. When Irina
insists that she can cut the wire and reverse ionization, Sloane reveals
that Elena had changed the wiring scheme as a fail-safe. Irina orders him
to take her to Elena so she can force her to reveal information while Syd
disarms the bomb.

Nadia fends off the mob and wanders the streets. She approaches a wounded
man who surprisingly holds a gun to her head and takes her to Elena. When
she refuses to join Elena, Elena injects her with the contaminated water.

Before Syd heads out to the rooftop to disarm the bomb, she turns to Vaughn
and says, "Just in case: yes, I'm gonna marry you." She wears his ring and
hops into the elevator.

Marshall tries to connect to the satellite. Weiss says the President and his
Cabinet are being evacuated to secret bunkers.

Sloane arrives with Vaughn, Irina and Jack. Vaughn searches for the relay
room. They strap Elena to a chair.

Sydney reaches the rooftop and opens a hatch that revealed hundreds of
interwoven wires. Nadia, now infected by the device, walks toward Sydney.
Jack and Irina urge a reluctant Syd to take her out. The sisters battle.
Vaughn blows the relay but nothing happens. Irina tells him to get to the
roof. Sydney knocks Nadia out and chains her up.

Vaughn arrives on the roof and realizes that Sloane is not there. Meanwhile,
Irina guides Sydney in disarming the device. Irina gives her sister a
chance to help them as Jack gets ready to torture Elena. When Jack pierces
her with a syringe, Elena yells that Sydney should cut the white wire.
Irina shoots Elena in the head and tells Syd to cut the blue wire instead
and run fast -- she only has 15 seconds.

Sydney is about to cut the wire when Nadia strangles her from behind with
the chain. As Sydney starts to suffocate, Sloane arrives and shoots Nadia.
Syd sees Vaughn and tells him to take the wounded Nadia with them. Syd then
cuts the blue wire and runs away as the device starts to fall apart. They
race inside the quaking building and sprints toward a shelter -- they have
just saved the world.

Jack advises Irina, who is wanted by the CIA, to disappear. They kiss. Irina
tells Syd that she's proud of her. She says that Syd may not see her on her
wedding day, but she'll see Syd.

Later, Syd visits Sloane in a jail cell, tells him that Nadia is stable, but
they're still trying to find an antidote. The Russian military executed all
survivors to support their claim that it was a chemical explosion. Sydney
has arranged for Sloane to see Nadia. She believes he was trying to do the
right thing. Sloane thanks her.

Driving in Santa Barbara, Syd suggests to Vaughn that they blow off the big
wedding and elope. After professing their love, Vaughn reveals that that he
was a bad guy before they met. He continues to say that to begin with, his
name is not Michael Vaughn. Before Sydney can react, a car collides with theirs.