After helping Preston Garvey and his crew get established in Sanctuary and finishing a few of his Radiant Quests, talk to Preston once more to speak with him about the Castle. Agree to help him take it back, and then head to the Castle location marked on your map to meet the rest of the Minutemen there.
The meeting place will be in a broken down building on the far east side of the map, near the shore. Preston will be waiting for you with several other Minutemen. Speak with Preston, and deliberate on how the group should follow through with the attack on Fort Independence. Several of the Minutemen will chime in with ideas, and it’s up to you to decide how you want to proceed.
After the planning phase, the Minutemen will reposition themselves near the Castle depending on the plan of attack you chose. We went with the Pincer Attack, which allows for flanking the area from two sides.
Once you reach the Castle, prepare to eliminate any Mirelurks or other irradiated creatures found in the courtyard. Clear the courtyard of enemies, and wait for further instructions from Preston. The plan is to have you hang back to clear out any eggs found in the courtyard while Preston and the other Minutemen clear out the walls.
Walk around the courtyard and destroy any egg nests that you find on the ground. They will also be marked with your compass on your Pip-boy, so they are pretty easy to find. Watch out for Mirelurks that may suddenly emerge from some of the nests. Clear out all of the eggs, and return to the courtyard.
It turns out that you have upset the Mirelurk Queen by destroying her egg-filled nests, and is ready to unleash her wrath on you and the other Minutemen. Watch out for the toxic sludge she will spew in your direction, and be ready to fight off handfuls of hatchlings that come to her aid. Try to lure the queen in different areas of the courtyard so that you can attack from cover.
When you’ve finally destroyed the Mirelurk Queen, regroup with the other Minutemen and speak with Preston in the courtyard. With the Mirelurks gone, the Minutemen can finally reclaim the Castle. Well done!
Now that you and the other Minutemen have successfully taken back the Castle, the only thing left to do is to get the radio transmitter up and running again by providing it with power. Luckily, there is a perfectly good Workshop workbench along the far wall.
Bring up the Workshop interface and navigate to the Power > Generators tab. The radio transmitter requires 10 Power before it can start running again, so you will need to build several generators to provide the transmitter with enough power. Two of the medium generators should do the trick, as these provide 5 Power each.
Place the generators within the courtyard, and attach wires from each generator to the radio transmitter. Once the radio transmitter is receiving power, speak with Preston Garvey one more time to conclude the quest.
With the newly powered radio transmitter, the Minutemen can now use it to broadcast Radio Freedom throughout the Commonwealth. Preston can also use this frequency to report new settlement locations that need your attention, so be sure to occasionally tune in. The Castle is now a living, breathing settlement, so make sure your new settlers’ needs are met.
Before you leave, make sure to snag the copy of Guns and Bullets magazine off of the table beside the radio transmitter to add it to your collection. If you need help finding more magazines throughout the wasteland, check out our Fallout 4 Magazine Locations Guide to find every issue.
Continue on to the Minutemen Quest: Old Guns, or return to the Fallout 4 Walkthrough and Guide.