The raid begins near the bottom of the ring as the party dismounts from a heat-shielded Pelican. The group starts along the bottom edge of the ring; they do some low-gravity platforming across scattered debris to reach a man cannon, which launches them through a hull breach.

The first areas of the raid take place in damaged Forerunner interiors (similar to the second mission of the campaign) with light from the nearby star blasting through from below, sending flames along the edges of platforms. Now and throughout the raid, players spawn equipped with a traditional campaign loadout: ARs and Sidekicks, but no equipment.

After making their way up past some Banished ground forces, the team reaches Encounter 1.

The party reaches a large, open area containing platforms connected by bridges, still along the bottom of the ring. The platforms are populated by Banished enemies, and teleporter pads on them will periodically release reinforcements to replace ones that have been killed. An exit is on the far end of the room, but it’s blocked by an energy gate, which is powered by three reinforced generators dotted across the entrance side of the chamber.

Two Hunters will eventually spawn in two of three possible places. Killing them causes a Banished Chieftain to enter through the gate, and when he’s killed, he drops a ball. This is the Targeting Beacon. When a player picks up the Beacon, an alarm goes off and a targeting indicator appears in the center of the room. The indicator tracks towards the Beacon with some momentum. When the two meet, a laser defense system will fire at the Beacon and unleash a powerful explosion, killing everything around the point of impact.

To complete the encounter, the party must bait the laser defense system into destroying the generators using the Beacon. However, the targeting indicator moves faster than a player can, so getting the Beacon to each generator requires organizing the party to throw it from one player to the next while contending with enemy reinforcements. The team needs to decide on a passing arrangement for each generator, and the level design leaves multiple ways to do so for each. If the Targeting Beacon is destroyed without taking a generator with it, then another Chieftain enters the room immediately; otherwise, two more Hunters arrive and the process restarts from the beginning.

Destroying the first generator escalates the encounter with additional add spawners, and destroying the second summons a pair of infected Spartans to attack the party. Once all three generators have been destroyed, the exit opens and the encounter ends when a player makes their way through it.

There is a vast gap in the Forerunner area inside of the Shard. A maze of walls and ledges occupies the center of the space. The entire team needs to cross this chasm to complete the encounter. Players begin in an entrance chamber containing Warthogs and weapons. To the sides of the room are two teleporters leading to asymmetrical control rooms overlooking the chasm. A large energy gated passageway is on the opposite side of the chasm, leading to an exit room with similar teleporters.

The control chambers contain buttons which incrementally build a bridge spanning the maze: both sides have buttons to add a straight piece and reset the bridge, but each can also add one type of turn (left turns on the left side and right turns on the right). Only three bridge pieces can be present at a time, with older ones decaying away as new ones are placed. The team must split up, sending two groups into the control rooms to build the bridge while a third crosses it in a Warthog.

To open the exit, the crossing players must kill an escalating number of Skimmers spread randomly throughout the maze, which are marked for the control room operators. Meanwhile, adds endlessly spawn into the control rooms and push towards the buttons, so the operators need allies to defend them. All of this must be done quickly to stay ahead of a wipe timer. When that timer is halfway depleted, a wave of sword-bearing infected spartans spawns across both control rooms.

Once the crossing players reach the exit, they are marked, resetting the wipe timer and allowing them to teleport directly between the exit room and the control rooms. They must then trade places with one of the control room teams so that they may cross, with that team later trading with the remaining group until everybody is marked, letting them leave the area and complete the encounter.

The underground ravine that Encounter 2 takes place in continues deeper into the ring, and the party makes their way further down it in an extended traversal section. Players get unlimited Repulsors in this section to allow for additional platforming. The group eventually reaches another Forerunner corridor connected to the ravine and takes an elevator to the surface.

This section mainly serves as a cool-down period following the highly involved second encounter and helps build the perceived scope of the players' journey.

The raid team now faces the giant tower that acts as the Banished's base of operation on the Shard. Starting in a cave with a Mongoose, a Warthog, a Razorback, and a Power Seed, they must race to the tower, make their way to the top, and plant the Power Seed in a socket on its highest floor. A wipe timer begins as the seed is picked up.

Reaching the base is the first challenge. Any player caught out in the open will be targeted by the laser system from Encounter 1, promptly annihilating them. To survive, the vehicles need to stay within a masking field around the Mongoose as they make their way across the rough terrain.

The tower is flanked by power supply facilities. Between them there are 12 fusion coils denoted by Covenant number symbols, and some of these are connected to energy gate inside the tower. The party must again split up into an inside team and an outside team. As the inside team makes their way up with the Power Seed, they must find terminals displaying which coil the nearby gate is connected to by its symbol. Which coil each gate is connected to is randomized each attempt.

The outside team, still in their vehicles, needs to find and destroy these coils while contending with the laser system and hostile Ghosts and Choppers. If they destroy a correct coil, then the associated gate temporarily goes down so the inside team can progress; if not, then the Mongoose's masking field loses power until the coil recovers.

The final gate requires two coils to be destroyed in quick succession. Once the seed has been planted, all enemies die and all gates go offline. The team regroups on an newly-activated teleporter to be taken to the final encounter.

The party at last finds itself facing Iratus on the roof of the tower. The AI has taken residence in a Sentinel combat frame and is protected by an impenetrable shield. This encounter is staged into 3 mechanics phases and 3 damage phases, all of which are accompanied by an unceasing tide of regular enemies.

For the mechanics phases, the goal is to hit Iratus with the returning laser system. A Chieftain arrives by Phantom shortly into the phase and once again drops a Targeting Beacon when killed. However, the Beacon cannot simply be thrown at Iratus -- he will override its fire control if it's going to hit him, rendering it inert. The team must first secure fire control for themselves.

Just before the Chieftain arrives, the party is alerted that an ally will be infected. A random player will then be replaced with a special Infected Spartan zombie. This zombie slowly wanders around attacking teammates with an Energy Sword, has very high defense, and will wipe the party if killed, so players need to evade and distract it as much as possible.

Meanwhile, the player who was infected will find themselves in a dark vision within their mind. They get a Bulldog shotgun with unlimited ammo and a flashlight, but are endlessly assaulted by regular infected Spartan zombies -- essentially, a classic Infection match. There are three monitors in this area, but they don't immediately display anything. If this player dies, their revive orb will be returned to the tower and someone else will be infected in their place.

At the back of the tower is a large control terminal with a pair of buttons. While the laser system is actively attempting to target the Beacon, this terminal will come online, showing four random symbols (from Encounter 3) that can be selected using a cursor controlled with the buttons. Three of these symbols must be selected, but the fourth is a trap that will kill the operator and reset the minigame. The correct symbols are shown to the infected player on the monitors around the dark arena while the minigame is active, so they need to communicate which ones they see to the operator outside.

The minigame must be completed quickly while the Beacon is being tracked. To prevent it from being locked on to, the other players need to juggle it between themselves in a game of keep-away. Another Chieftain will arrive if they fail, but the minigame will still be randomized and reset.

Once the minigame is complete, the team is told that they have fire control. The laser will now only fire when a third button on the tower is pressed. One player needs to let the laser system lock on to the ball and throw it at Iratus while the operator presses the fire button as it reaches him, finally breaking his shield and beginning a damage phase. This also frees the infected player.

The damage phases are a much simpler matter of shooting the boss a lot. Adds continue to spawn during these, but unlike in Destiny, there is no time limit; the phase will only end once a third of the boss's health has been depleted, whereupon another mechanics phase will begin.

While following phases are much the same, more difficult adds will spawn beginning with the second mechanics phase. The third damage phase acts as Iratus's final stand. The AI's defense and damage greatly increase, and he now directly targets players with the laser. Red circles warn the team of incoming strikes, which will instantly kill allies and enemies alike.

The raid is complete once Iratus is killed once and for all.