The Command Spire
From Halopedia, the Halo wiki
The Chief continues his ascent to the Command Spire via the Gravity Lift, which runs in parallel with four purple-yellow energy beams (the same color as the beam weapons used by Zeta Halo's Sentinels).
The Chief arrives inside the Command Spire.
Aggressor Sentinels attack the Chief as he steps off the elevator.
If the Chief tries to access the terminal before killing all the Sentinels:
The Chief eliminates the attacking Sentinels.
The Chief deploys the Weapon onto the terminal.
The Weapon shoots the Chief a cold look, before turning around and hacking the terminal.
She turns her attention back to the data.
She turns to the Chief.
She points upward with both hands.
The Chief starts to reach for the Weapon, but pauses, as if expecting her to say something else. When she remains silent, he uploads her back into his armor.
A section of wall lowers itself and splits apart, exposing a shaft through which one of the four energy beams flows.
If the Chief gets too close to the beam:
Avoiding the beam, the Chief uses his Grappleshot to climb the platforms and ledges surrounding the beam, moving himself up the shaft in a circular fashion.
The Chief doesn't reply.
The Chief ignores her and continues to climb the energy beam shaft. After reaching the top of the shaft, he steps into an adjacent chamber containing a Crucible. After eliminating the Sentinels patrolling the room, he searches for a Power seed.
If the Chief spends too much time wandering around:
The Chief locates a Power seed, retrieves it, and returns to the Crucible. After dealing with another Sentinel patrol, he inserts the power seed into the Crucible. A seal on center of the floor slides open, enabling the gravity lift below to extend to this section of the Spire. The Chief enters the gravity lift and ascends to the next level.
Arriving at the next level, he finds racks of Banished weaponry, indicating the presence of Banished troops in the immediate vicinity. After arming himself appropriately, he heads up a ramp and discovers a manufacturing chamber behind a glass window. Within the chamber, the Forerunner machinery is busy assembling the components needed to rebuild the Silent Auditorium.
The Chief continues his journey up the Spire and soon encounters Banished troops and the Harbinger's Skimmers.
The Chief fights his way through many enemies, including a Sangheili Warlord. He then steps onto a portal and is teleported to another section of the Spire. He fights his way through several chambers, where the newly forged building blocks are being transported through the Command Spire.
In the third transport chamber, he overhears a couple of Unggoy conversing.
The Chief eventually finds another gravity lift, which he uses to ascend to the next level. He then enters a much larger transport chamber, where he has to fight through Banished, Skimmers, and Sentinels, all united in defense of the Reformation.
After defeating all these enemies, the Chief finds another floor portal and teleports to a hallway.
The Master Chief enters the next chamber, where he finds a very unwelcome surprise waiting for him.
For Adjutant Resolution's dialogue during the fight, see here.
Sentinels arrive to reinforce the Sub-Monitor.
True to his word, Adjutant Resolution's new combat chassis is much more powerful and durable than the previous version. Nevertheless, after a lengthy battle, the Chief manages to defeat both the Sub-Monitor (again) and his "friends".
The Chief locates the elevator and rides it up to the Observation Platform.
Fade to black.
The Chief arrives at the Observation Platform. A contingent of Banished troops is also present.
The Chief eliminates all Banished troops. The shield surrounding the Platform then lowers, and a Banished Phantom attacks.
Fortunately, the Banished have stocked the Observation Platform with a number of heavy weapons which the Chief arms himself with. He either outright destroys the Phantom or disables all of its weapons, forcing it to disengage.
A second Phantom arrives almost immediately after.
On cue, a third Phantom arrives.
Even for the Chief, fighting two Phantoms at the same time is not an easy task. Eventually, though, he either destroys the Phantoms or disables their weapons and forces them to retreat.
The Chief deploys the Weapon onto the Platform's terminal.
The Weapon uses Despondent Pyre's Encephalon to access the Spires.
Scene focuses in on the Weapon.
She turns to the Chief, who has his back to her.
The Chief abruptly turns around to face her.
He trails off, unable to continue.
He turns away from her.
Echo 216 arrives.
The Chief steps towards her.
The Pelican is close enough to the Platform that the Pilot can now be seen in the cockpit.
Jega starts stabbing at the Pelican's controls with his crimson energy sword.
The Chief leaps off the Observation Platform and onto the Pelican's cockpit. He starts punching the canopy, attempting to get inside and save the Pilot, but to no avail. The Pilot struggles with the damaged controls and the Pelican bucks wildly, throwing the Chief off and back onto the platform.
The Pelican, now under Jega's control, flies away from the Spire.
The Weapon is taken aback by this order.
The Chief turns to her.
The Chief thinks it over for a second before making his decision.
The Weapon grunts as she extracts large quantities of data, before thrusting her hand out and unleashing a pulse.
The Chief retrieves her and dashes into the portal.
The following achievements can be unlocked on The Command Spire across the all editions of Halo Infinite.