The Lost Patrol

The Lost Patrol is a quest in Fallout 4.

Quick walkthrough

 * 1) Investigate the battle site.
 * 2) Listen to Knight Astlin's holotape.
 * 3) Investigate the Revere satellite array.
 * 4) Follow the radio Distress signal.
 * 5) Listen to Scribe Faris' holotape.
 * 6) Follow the radio distress signal.
 * 7) Investigate the battle site.
 * 8) Listen to the Battlefield holotape
 * 9) Investigate Recon Bunker Theta.
 * 10) Speak to OR kill Paladin Brandis, depending on relation to the Brotherhood (ally/enemy).
 * 11) If Paladin Brandis is spoken to: Report to Danse.
 * 12) If Paladin Brandis is killed, the quest is marked as completed.

Detailed walkthrough
The player character can find another in a ruined house next to Knight Varham. The ruined house is north of Relay Tower 0MC-810, south of Greentop Nursery and east of Taffington boathouse.

The next may be found next to the corpse of Knight Astlin in the back of the National Guard Recruitment Centre. This is accessed by approaching the National Guard Training Yard from the East. Namely, by fast travelling to Revere satellite array, running west to the Yard, across the parking lot and through the door under the "marquee".

One can find the origin of one distress signal in the Revere satellite array next to Scribe Faris, at the top of one of the four non-central towers.

Bugs

 * If the player character puts off completing this quest until after Paladin Danse has become a potential companion, they may be unable to turn the quest in as he will only offer companion dialogue options. However, after a period of time the mission turn in point will be transferred to Captain Kells, allowing for completion.
 * Captain Kells will give generic dialogue instead of allowing the player character to turn in the quest until after they've completed Show No Mercy for the Brotherhood of Steel.
 * Speaking to Brandis (or simply entering the National Guard Training Yard) may cause you to lose Fast Travel capability. Every time you open the map, the same message will appear: "Fast Travel is currently unavailable from this location." This message appears anywhere, even if there are no enemies around, you are not overencumbered, and are not in a building.