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Precipice of War
Fallout 4

Precipice of War

Follow our Fallout 4 guide to complete the 'Precipice of War' quest. Learn how to fight the Brotherhood of Steel, secure a Vertibird, and infiltrate the Prydwen.

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Follow our Fallout 4 guide to complete the 'Precipice of War' quest. Learn how to fight the Brotherhood of Steel, secure a Vertibird, and infiltrate the Prydwen.

Walkthrough
  1. 1
    Fight off the initial Brotherhood of Steel attackers at the Old North Church.
  2. 2
    Speak with Desdemona and enter the catacombs.
  3. 3
    Find Glory in the catacombs, make a promise, and she will die.
  4. 4
    Fight through the catacombs and back up to the Old North Church, defeating Brotherhood soldiers and Paladin Brandis (if rescued during 'The Lost Patrol').
  5. 5
    Talk to Desdemona again; she will devise a plan to attack the Brotherhood.
  6. 6
    Travel to Cambridge Police Station to secure a Vertibird. It's recommended to equip Charisma-boosting gear and chems (Mentats, X-Cell) and use Stealth Boys if possible.
  7. 7
    Meet Tinker Tom at Cambridge Police Station. He will explain the objective: clear the area and allow him to work on the Vertibird.
  8. 8
    Engage the Brotherhood forces outside the station, including a Knight in Power Armor and other soldiers. Use sneak attacks and try to disarm the Knight or take his Fusion Core.
  9. 9
    Clear the courtyard and then head inside the police station.
  10. 10
    Eliminate Brotherhood Soldiers and Scribes inside, including Scribe Haylen. Destroy the two turrets in the lobby.
  11. 11
    Create a killzone for enemies entering from the left. Use grenades if necessary.
  12. 12
    Clear the entire Cambridge Police Station, including the Motor Pool.
  13. 13
    Speak with Tinker Tom, who will give you 'Explosive Charges'.
  14. 14
    Head to the roof and prepare for an ambush by Brotherhood soldiers.
  15. 15
    You can either use the Minigun on the stolen Vertibird or shoot down incoming Vertibirds and soldiers.
  16. 16
    Speak with Deacon, who will give you a Brotherhood of Steel Outfit. This concludes 'Precipice of War' and begins 'Rockets' Red Glare'.
  17. 17
    For 'Rockets' Red Glare', board the Vertibird with Tinker Tom.
  18. 18
    Upon arriving at the Prydwen, equip the Brotherhood of Steel Uniform and any Charisma gear. Stealth is optional but can lead to higher XP gains through speech checks.
  19. 19
    Head west from the Vertibird's docking area, up stairs, through a doorway to the Prydwen Command Deck.
  20. 20
    Continue west around a stairwell, then up a ladder to the Prydwen Main Deck.
  21. 21
    Go up stairs to the right and interact with Quinlan, passing a speech check.
  22. 22
    Continue up stairs, head south, then up stairs west, and enter a tunnel north to find the first 'Gas Bag Valve'.
  23. 23
    Plant an Explosive Charge on the valve. If caught by a Senior Scribe, pass another speech check.
  24. 24
    Continue north and plant the remaining two Explosive Charges. Passing a hard speech check allows planting all charges peacefully; otherwise, use Stealth Boys to avoid the Senior Scribe.
  25. 25
    Return to your Vertibird and depart.
Tips
  • Bring Charisma-boosting gear and chems (Mentats, X-Cell) for speech checks.
  • Stealth Boys can be useful for avoiding combat and passing speech checks.
  • A shotgun is effective for close-quarters combat inside the police station.
  • Consider disarming the Knight in Power Armor at Cambridge Police Station to obtain his Fusion Core.
  • If you can't pass speech checks, use Stealth Boys to plant the charges on the Prydwen undetected.
  • 590 XP
  • 500 Caps
  • Plasma Cartridge x5
  • Plasma Grenade x2
  • Pulse Grenade
  • Short Plasma Rifle
  • Stimpak x2

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