Mission 7: The Library

Mission Objectives

1. Follow 343 Guilty Spark through the index corridor

   Guilty Spark floats ahead of you through a narrow hallway. Do not rush after him — the doors he opens trigger Flood spawns behind you. Let Spark reach each door first, count to three, then advance. This spacing prevents combat forms from spawning directly on top of you.

2. Hold the first elevator room

   The elevator room is a circular arena with multiple entry points. Flood pour in from every opening. Post up against the central pillar and rotate around it as enemies enter. Shotgun everything at close range, Magnum for carrier forms that waddle in — shoot carriers as far away as possible because their explosion spawns infection forms.

3. Survive the corridor gauntlets between lifts

   The corridors between lift rooms are the mission's meat grinder. Combat forms with rocket launchers appear here — their rockets track poorly but one-hit kill. Listen for the distinct rocket-launch sound and immediately strafe perpendicular to the corridor. Floors two and three introduce Flood with active camouflage.

4. Defend the final Index chamber

   The Index chamber is four floors of Flood spawns while Guilty Spark retrieves the Index. This fight lasts roughly four minutes with no checkpoint. Stay on the top floor until Flood overrun it, then drop to the third floor, then the second. Do not go to the ground floor — you will be surrounded. Grenades over the railing clear the lower floors safely.

Boss Strategy

No dedicated boss, but the four-floor Index chamber defense is essentially an endurance boss. You must survive approximately four minutes of continuous Flood waves. Key tactics: stay on the upper floors and drop down only when overwhelmed. The shotgun is mandatory — no other weapon clears infection swarms fast enough. Frag grenades tossed over the upper railings will clear the lower floors without exposing you. Carrier forms are priority targets; shoot them as they enter the chamber because their explosion chain-reacts into nearby combat forms. If you run low on shotgun ammo, the Magnum kills combat forms in two headshots. On Legendary, accept that you will die and memorize the spawn patterns; survival is about positioning more than aim.

Collectibles

• Terminal 7 — On the central pillar of the first Index elevator room
• Skull: Catch — Behind a pillar on the second floor of the large circular chamber

Secrets & Easter Eggs

• Rocket launcher flood ammo exploit — Flood combat forms that carry rocket launchers drop extra rockets when killed. Instead of killing them immediately, let them fire first — they will often fire two rockets before reloading, and each shot consumes a rocket from their invisible ammo pool. Kill them immediately after the second shot to maximize rocket drops.
• Checkpoint optimization strategy — the mission saves checkpoints when you enter each elevator room. If you die in a corridor section, the game restarts you at the previous elevator. Play aggressively in corridors to reach the next elevator quickly rather than cautiously clearing every Flood — the elevator checkpoint is worth more than clean corridor fights.
• Alternate ammo route — in the second elevator room, take the left exit instead of following Spark. It leads to a dead-end room with four shotgun ammo boxes and two health packs. The detour costs twenty seconds but provides enough shells to carry you through the next two corridor sections.