I don't even see the point of having a Mirelurk Queen at The Castle. I finally got around to exploring the place... came in along the coastline from the south... found a way on top of the fort where I decided to dispose of several hatchlings (without bothering to speak to Preston first) Next thing I know, the Mirelurk Queen appears, far off in the distance. Now, I still haven't talked to Preston, but all the Minutemen there are shooting at The Mirelurk Queen, on the opposite side of the fort, while I prepare for battle/ scrap a few things from the fort interior.
Awesome. THIS MONSTER looks like a challenge.
Then, some Bethesda hand-holding thing happened that I have NEVER seen before... but for what reason, I cannot even begin to understand why:
1) I was allowed to fast-travel, even while the Mirelurk was attacking me and the Minutemen.
2) The Minutemen killed the Mirelurk Queen FOR ME while I was looking for supplies inside the fort.
3) I didn't have to fire one bullet at this monster. (see #2)
4) I never even had to speak to anyone at The Castle before initiating the killing of hatchlings or Mirelurk Queen.
Question: How is this not a flaw in the game's design? Patch it!!