Floodgate (Level)

Floodgate is the fifth campaign mission of Halo 3.

This is also the first level in Halo 3 which you encounter the Flood. Upon disabling the Anti-Air Gun in The Storm, a Flood-controlled Covenant cruiser crashes in Voi. In order to eliminate the infestation, Master Chief and the Arbiter must overload the crashed cruiser's engines, wiping out the entire city and the Flood with it.

Upon completing it on the Normal, Heroic, or Legendary difficulties, the player will earn the "Cleansing" achievement and 30 Gamerpoints.

Transcript
This transcript is incomplete, and comes from an incomplete source of Floodgate's gameplay

01: It Followed Me Home
gameplay begins

Miranda Keyes: The Flood. It's spreading all over the city.

Lord Hood: How do we contain it?

Miranda Keyes: Find the crashed Flood ship, overload its engine core. Either destroy this city, or risk losing the entire planet.

Lord Hood: Do it.

Miranda Keyes: Chief, make your way to the crash site.

some time later, when entering the city

The Arbiter: (unintelligible)

Marine Sergeant (possibly Stacker){over COM}: All squads, report!

Marine squad leader {over COM}: Multiple contacts, unknown hostiles.

Marine {over COM}: There! Over there! We're surrounded, Sergeant!

COM system: {Flood screams are heard}

Marine {over COM}: Aaaaah!

You find a group of Marines in a loading ramp.

Marine Sergeant: Fall back, fall back!

Female Marine: Sergeant, come on!

''Infection Forms and Combat Forms (including the new Brute ones) descend on the Marines, infecting and killing or forcing you to kill them. The female Marine who had spoken earlier is the only survivor.''

Female Marine (upon spotting the Chief): About damn time!

''The Marine accompanies you into a building, where you run into a lone Marine fighting off a horde of infection forms. It is possible to save him, but more often than not, he will be mutated before your eyes.''

A Marine gets infected in the level, Floodgate. (Double-click for larger video) N-bCMhBINiA