This guide will help you complete the Railroad Quest: Precipice of War in Fallout 4. Fight to protect the Railroad headquarters as hostiles approach from multiple directions. Follow our guide and complete each objective to secure the Railroad HQ.
You’ll be faced with a lot of heavily armored enemies in the fight ahead. Prepare yourself by bringing along heavy weapons and explosives, such as grenades. Consider wearing your Power Armor suit as well for additional protection.
After completing the Railroad Quest: Underground Undercover, speak with Desdemona to warn her of the impending enemy threat. Upon hearing the news, Desdemona quickly mobilizes the Railroad agents into defensive positions.
Defend Railroad HQ
By the time you deliver the news to Desdemona, you’ll find that Brotherhood of Steel forces have already arrived upon your doorstep. Defend the Railroad HQ as Brotherhood Knights detonate the escape tunnel. If you have grenades, chuck them down the narrow hallway to deal additional explosive damage to incoming enemies. Use heavy firepower to wipe out any hostiles trying to infiltrate via the escape tunnel.
Talk with Desdemona
After clearing out the initial wave of hostiles within the Railroad HQ, speak with Desdemona once more to discuss how to proceed. Since the escape tunnel has been destroyed, the only other escape route is through the catacombs. Check on Glory in the catacombs and help her clear the way for the other agents.
Secure the Catacombs
Head through the south door leading to the Old North Church. As you enter the passageway, you’ll find Glory at the foot of the entrance tunnel near the steps. Speak with her, then prepare to defend against another wave of intruders as the Brotherhood breaches the hideout entrance.
Secure the Church
Proceed through the catacombs to reach the main floor of the church, eliminating any hostiles you encounter along the way. There are several Brotherhood Knights waiting on the main level, so be sure to reserve ammunition in your heavy weapons to take down these armored foes with ease.
Talk with Desdemona
After clearing out the hostiles on the main floor of the church, speak with Desdemona for further instructions. It’s time to take the fight to the Brotherhood, in retribution for their attack on the Railroad HQ.
Meet Tinker Tom at the Police Station
Desdemona’s risky plan involves hijacking one of the Brotherhood’s Vertibirds. There happens to be one parked on the rooftop of the police station, and it’s up to you and Tinker Tom to steal the flying war machine out from under the Brotherhood’s noses. Travel west and meet Tinker Tom at the Cambridge Police Station to proceed with the plan.
Eliminate Brotherhood Forces
Tom will be waiting at a bus stop up the street from the Cambridge Police Station. Speak with him about the mission, then proceed towards the station.
There are a few Brotherhood soldiers firing from the police station rooftop. Take cover and eliminate these enemies first before approaching the entryway. Prepare to gun down several Brotherhood soldiers at the front of the building, including at least one Power Armor clad Brotherhood Knight. Enter the police station, and eliminate all hostiles. Head up the staircase in the back hallway to reach the rooftop, and watch out for the laser turret in the corner above the door.
Talk with Tinker Tom
Once you reach the rooftop, speak with Tinker Tom to discuss how to proceed. Take the explosive charge, and get ready to fight off a few more enemies as Tom prepares the Vertibird.
Defend the Vertibird
Defend Tom from the incoming Brotherhood forces as he tries to get the Vertibird working. Take out the Brotherhood Knights that drop in from the sky, then eliminate the enemy Vertibird. For some additional firepower, hop onto the parked Vertibird and use the minigun turret to mow down the Brotherhood foes.
Talk with Deacon
Now that the last of the Brotherhood forces have been eliminated from Cambridge Police Station, there’s no one left to stop you from taking the "Claymore" Vertibird. Speak with Deacon to receive a new plasma weapon and ammunition. With the Vertibird ready for departure, the Precipice of War quest ends, and the Rockets’ Red Glare quest begins.