boost.

From the Grunt valley, head right to another valley of Brutes. At the bottom, two Brutes await. Approach them head-on in the Chopper, but avoid direct collision as they are fragile.

At the top of the hill, a Brute blockade blocks access to the bridge. Stay back and out of range of the fuel rod Brutes.

Cross the bridge to the Brute encampment. Focus on the red turret before eliminating other Brutes.

After destroying everything, a Pelican arrives. Follow it across the valley, engaging a detachment of Jackals and Grunts in a shadowy base.

Enter the cave to find the landing zone. Clear the surrounding Brutes and a Covenant Wraith.

Skip the land bridge and Brutes behind the barricade for now. Drive the Chopper into the basin and up to the Wraith. Exit the Chopper and fight the Wraith on foot, using fuel rods or shield-sapping equipment if available.

Return to the Chopper and drive towards the zone entrance. Ignore the Brutes crossing towards you from the land bridge.

Focus on the two Ghosts that approach. Use the Chopper's range to engage them from afar, or try to acquire a Ghost for better maneuverability.

Once the Brutes and vehicles in the basin are cleared, you should receive a checkpoint. Ensure any Grunts manning gun placements or hiding near the Wraith's former location are eliminated.

Proceed past the Wraith's corpse to the anti-aircraft weaponry. Use energy turrets to eliminate the Brutes and the two anti-aircraft tanks.

After the tanks are destroyed, Miranda Keys' ship lands. Grab a tank and proceed with the escort mission for the Guilty Spark to the gold gates.

Drive the tank through the level, destroying enemies. Fire at the glowing engines of any Covenant dropships to destroy them.

Use the tank to clear the Brutes on the bridge. Master Chief and 343 Guilty Spark will open the door.

Follow the Spark and activate the button to expand a bridge.

Reach the second terminal (t02).

Head outside, board a Warthog, and man the turret.

After clearing Wraiths and Ghosts, a Scarab appears. To defeat it, commandeer a tank and park it underneath the Scarab. Shoot the purple flappy things over its knees to make it land.

Use the gray lifts in a nearby building to get onto the Scarab. Find and destroy the power core.

SKULL ALERT: To get the Cowbell Skull, pick up a gravlift from the small structure protruding from the sand after the Scarab is dead. Hold onto it until instructed.

The Elite commander reports the Brute fleet is crippled. Continue up the spire to confront the Brute leader.

Drive the Brute Chopper up the ramp and use it against enemies on the lower tiers of the spire. Use a fuel rod gun and carbine for the next area.

In the next section, the Arbiter and soldiers are dropped off. The Guilty Spark opens doors to a room of sleeping Grunts. Melee attack each Grunt without alerting the others.

In the back corner, a Brute with his back to you can be approached stealthily.