So, I just got to the Battle of Bunker Hill via the Railroad path and, to say the least, I'm a bit perplexed about what was going on there. (Disclaimer: I haven't done multiple playthroughs, so I hope these questions don't seem too boring to everyone.)
Desdemona asked me to go there and sabotage the mission to capture the escaped synths, so I took out the first couple of synth soldiers that were attacking the Railroad heavies, and then ended up having to shoot X4-18 as well when he opened fire on a Railroad Heavy. However, in the midst of all this, the Brotherhood of Steel started attacking...somebody? I could tell they were firing on the Institute Synths, but it also looked like they were shooting at the Railroad Heavies and/or the vendors and caravan guards who normally hang around Bunker Hill, and meanwhile a couple of mutant hounds somehow found their way into this whole mess. I tried to defend the locals and the Railroad Heavies from the Brotherhood, but then it seemed like the Railroad Heavies and Caravan Guards were fighting each other as well.
Eventually I found my way underground and helped the Railroad Heavies defeat a Brotherhood knight and a couple more Institute Synths, even though the turrets were firing at me for some reason. I talked to all four escaped synths, and they all thanked me and said they'd find a way out after I left, but the little quest markers continued to appear above their heads and the quest did not update in my PipBoy. When I exited the underground passage, the vendors and caravan guards were still in that crouched down "hiding" pose but nobody was fighting any more. There didn't seem to be any Railroad Heavies still around, but there was one Brotherhood soldier just standing motionless outside the gates to Bunker Hill.
What I'm trying to figure out here is:
1) What is the Brotherhood doing there? I didn't go very far with their quest line - i helped them out at the Cambridge police station but turned down the offer to join, though I do try to help them whenever I see their Vertibirds getting into fights with raiders or Super Mutants. I figured I was basically on friendly terms with them, but if there's some way to find out what they're doing or persuade them not to attack Bunker Hill, I must have missed it by a lot.
2) Are the Caravan Guards and Railroad Heavies in fact shooting at each other? This one honestly left me perplexed as to which side to take - I'm a pretty strong Railroad ally, but I definitely didn't sign up for an attack on civilian caravan guards. Plus it seems dumb for the Railroad anyway, given that Stockton is an asset to them and they were already facing the Institute and the Brotherhood. Part of the reason I just headed for the underground passage was that I hoped the heavies and guards would stop fighting if I got the quest to advance.
3) Is the quest bugged given that nothing happened after I talked to the escaped synths? Should I try going back to them again after talking to Father over at the C.I.T.? It wasn't clear that anything else in particular needed to be done - if there was a door I was supposed to unlock for them or something like that, it must not have been marked.
Thanks to anyone who can help clear some of this up!