On October 20, 2552, (during the events of Halo 2) the Rookie and his squad, along with other ODSTs, were stationed aboard the UNSC Battle Cruiser(Designated - [Classified]), with only one mission, to take out the Prophet of Regret, who was aboard a Covenant Batle Crusier positioned above New Mombasa. At the last moment before beginning the drop, ONI operative Dare took control over Buck's squad, to use them for a classified mission. The Rookie himself, however did not hear this because he was asleep at the time. He was informed of the change in mission when Buck alerted the team to an emergency debrief.
As Buck's squad was dropping toward the covenant ship, Dare changed the team's course so that they would land close to ONI Alpha Base instead. Moments before they were going to hit the ground the Covenant ship went into slipspace, generating a massive shock wave and an EMP blast, scattering all of the pods across the city. Rookie's pod, in particular, smashed into Mickey's pod, cracking the pod's window and throwing the Rookie into free fall. The Rookie was knocked unconscious, only to awaken six hours later.
The Superintendent, the municipal AI of New Mombasa, helpfully uploaded a map of the streets to his VISR database, and lighted the way so that he could get through the city safely. As the Rookie explored the city more and more, he tried to piece together clues to figure out what happened to his squad mates while he was unconscious, avoiding and engaging Covenant patrols all the while. With each 'beacon' he located, the Superintendent would show him some security footage showing a piece of the puzzle, helping him track his squadmates.
The Rookie eventually found all the beacons left by his squad and discovered they had escaped New Mombasa without him. However, he then receives a distress call from Dare, requesting assistance in the city's underground catacombs. After narrowly escaping a Covenant ambush, he arrives in the underground and comes across an N.M.P.Q officer who was left stranded in the catacombs too. They team up and navigate through the tunnels. At this point, one of two things will happen. If the player has collected all the Audio Logs, the police officer will stop and will unlock an door to an secret room and then ask you to wait outside. If you go inside then he attempts to kill you, this is an attempt to cover up evidence of police corruption and murder. If the player hasn't collected all the Audio Logs, then the officer is ambushed and killed by a swarm of Drones.
Once the Rookie found Dare, she ordered him to assist her in getting to the Superintendent's core. Once they reach the core, Dare and the Rookie discover that "Vergil", a sapient intelligence within the Superintendent program, has been transferred into a Covenant Engineer, an organic supercomputer of Forerunner origin, which now work as slaves for the Covenant. Vergil contains valuable information about the Covenant's motives and what there searching for. The Rookie and Dare both make their escape with Vergil, but are greeted by a group of Brutes who were waiting to ambush them. However, Buck makes a return and helps the trio kill the Brutes and make a getaway.
After escaping the data hive, Buck suggests using the highway to escape the city. Once they arrive on the Highway, Vergil commandeers an Oliphant garbage truck (a civilian version of the Elephant) and the Rookie and Buck escort the truck down the highway in a Warthog. Whilst driving down the highway a Covenant cruiser jumps in from slipspace and begins glassing the city, forcing the team to stop and wait for evacuation. After fending off numerous waves of Covenant, the rest of the squad arrive in a hijacked Phantom and pick them up. As they're about to leave, the Covenant Cruiser arrives above them and prepares to excavate the area. The team narrowly escapes.
A month later the Rookie is seen with his squad, asleep once more, as the squad meet up with Sergeant Johnson, who has arrived to oversee the interrogation of Vergil.
- Name: Classified (though initials are "J.D.")
- Height: 6'1"
- Rank: Lance Corporal
- Home World: Luna (Earth's moon)
- Weight: 160lbs