Rescue Initiate from the Hub

A Brotherhood of Steel Initiate has gotten himself captured in the Hub. He's being guarded by several tough guards (be careful if you are a low level character) who carry the equivalent of a platoon's worth of firepower. They will shoot on sight.

Walkthrough
Go to the Hub's Old Town, in a building just below the entrance to the area. If you manage to rescue him without getting blown away, then there's a nice reward waiting in the BOS base. When you talk to Talus, you get the option of recieving a Laser Pistol, Rocket Launcher, Super Sledgehammer or Power Armor (one of only two sets in the game which can be obtained peacefuly).

Behind the scenes
Upon entering the ambush house, sometimes one of the thugs will say "Have you ever danced with the devil in the pale moonlight?". This is a quote by the Jack Nicholson portrayed Joker in the 1989 smash Batman.