From Halopedia, the Halo wiki
The Master Chief finds himself in a tunnel that the Banished are using as a storage facility. After scavenging supplies, he explores the area, and comes across a Cylix. The humanoid figure engraved on this Cylix is yellow instead of blue and has a very prominent bulbous head along with other distinguishable features. More importantly, however, this Cylix is open.
John proceeds further into the tunnels and comes across an Unggoy patrol.
The Chief catches the Unggoy off guard and wipes them all out. He enters a command center of some sort.
The Chief deploys the Weapon onto the terminal.
A hologram of Escharum materializes in front of them.
John uploads the Weapon back into his armor.
Zoom in on Escharum's face.
The wall behind the Master Chief lowers itself, forming a ramp that leads outside. Sunlight floods the room. The Chief can now see the rest of the Banished Outpost which has been established next to the wreckage of a UNSC frigate.
The Chief steps outside and onto the surface of Zeta Halo. A Banished Phantom flies overhead. A war horn sounds.
The Phantom drops off reinforcements.
The Chief engages the Banished forces.
The Chief eliminates most of the Banished in the immediate area.
Another Phantom swoops in and drops off additional reinforcements.
After all the Banished have been eliminated:
The Chief finds a terminal and deploys the Weapon.
The Weapon studies a hologram of the crashed UNSC frigate where the base has been established.
She snaps her fingers. The hologram dissolves.
Echo 216 descends and lands next to them. The Pilot emerges from the Pelican. He drops to his hands and knees and kisses the ground.
He looks up at the Chief.
The Chief opens his palm and the Weapon's avatar appears.
The Pilot recoils in alarm.
Terrified, he takes cover behind the Pelican, before staggering to his feet.
The Weapon turns to address the Pilot.
She suddenly turns to the Chief.
TACMAP is activated.
The Tower's location is highlighted on the map.
Outpost Tremonius is highlighted.
Outpost Tremonius now reads as being under UNSC control.
TACMAP is disengaged. The Weapon's avatar switches off. The Chief turns to leave.
Resigned, he goes back inside the Pelican, muttering to himself in Spanish.
The following achievements can be unlocked on Outpost Tremonius across the all editions of Halo Infinite.