Data Hive

Data Hive is the second-to-last flashback mission in Halo 3: ODST. It is set in the immense data facility below the city of New Mombasa, where the Covenant are trying to gain access to the Superintendent's data core. It is the first linear level in the game after the hub.

Summary
The level begins as the Rookie, having followed Dare's distress signal, descends down a subway elevator shaft, into the Superintendent's Data Center deep under the city. He ends up on sub-level 7 of the complex, and has to fight his way down to sub-level 9 where Dare is currently holding out. Upon arriving there, they fight their way through a Drone hive to the core of the Superintendent to secure its core data. Inside the data core, they meet a Huragok who has combined the Superintendent's data with its own, making it extremely valuable. Buck then arrives at the complex, and they escape to the surface through heavy Covenant resistance.

Trivia

 * At one point in the level, the player will encounter an NMPD officer. The Superintendent is seen acting strange towards him, such as not opening data stacks for him to allow access or saying phrases like "Warning: hitchhikers may be escaped convicts."(A possible reference to the final segment of the level The Maw in Halo: Combat Evolved).
 * If 29 of the Audio Logs haven't been found, the cop will be killed by Drones, but if the player has found them, he will lead him to a normally-locked room; he will tell the player to wait outside, but if followed, he reveals he was under orders from Commissioner Kinsler to make sure Dr. Endesha was dead and that no one knew about it, this also reveals the true purpose of the teams mission; To kill the Huragok in the Superintendent's core and recover the core data. He then tells the Rookie that he knows too much and that he must be eliminated by the death loop; Making this character the first human enemy(besides the Marines in Sacred Icon and Quarantine Zone) in a Halo game. After the player kills him, the Superintendent will say "Crime doesn't pay. Good citizens do their part".
 * It is interesting to point out the speed of which the Drones can create a suitable Hive to breed and live in, considering the short timeframe between the Covenant attack and the setting of this level. This is partially explained by two grunts seen conversing in the level, who point out that the Yanme'e spent most of the time building their hive and not sealing the entrance to the tunnel.
 * Around the level, there are multiple monitors which show data of the Superintendent's status. If the player goes too close to these screens, the Superintendent will interrupt the displays, labeling the information as classified.
 * There are two different cutscenes that can be played when Dare and the Rookie meet the Huragok, Vergil. The normal cutscene is viewable if the player has not collected all 30 audio logs, and shows the Rookie arming his gun and aiming at Vergil, with Dare telling him to stand down. If all 30 audio logs are recovered, it is Dare that aims at Vergil, with the Rookie motioning for her to stand down, then whistling to Vergil to come over, reflecting the information gained from the logs.
 * During the level, you can see Drones feasting on the deceased NMPD bodies.