If you’ve decided to work with the Brotherhood of Steel in your Fallout 4 adventure, you’ll be asked to go ahead and try and find the locations of a patrol that have not been heard from for quite some time.
The Lost Patrol quest requires you to go and find out the whereabouts of the lost patrol through a bunch of beacons which will emit a pinging noise the closer you get to them. There are four parts to this quest and some of them can be particularly tricky to come across. The quest also seems to have been a bit glitchy for some players with the beacon noises not pinging at all. Here are the locations of the lost patrol to help you out.