As head of security, Ramos is responsible for protecting the chapter from outside threats. Under McNamara's command, this includes ensuring the integrity of the lockdown, preventing personnel from within leaving and those without from returning to the bunker. He only makes exceptions for supply runners, high security patrols, and the occasional pair of Initiates trying to get a feel for the surface. He pays attention to details, but he isn't heartless, after all.[2]
That's not to say he's lenient. Ramos is a veteran of Operation Sunburst who survived both the NCR siege and McNamara's desperate counter-offensive west. As a result of his experiences, he despises Elder Elijah and his lapse in command and will be the first to execute anyone not of the Brotherhood to ensure its ideals are upheld and the chapter safe. His diligence ensured that there were no incidents for over a year, that is, until the Courier arrives at the chapter's doorstep.
Still in the Dark: If the player enters the bunker without Veronica, he apprehends the player and brings them before the Elder. Otherwise, he will chew Veronica out a bit, then clear her for entry, together with the player. In the later parts of the quest, if the player elects to support Head Paladin Hardin against Elder McNamara, Ramos can help point the player in the direction of the data stores in order to find a precedent to oust the Elder.
Although Ramos respects the Elder, he is still a Brotherhood hardliner and will be promoted to Head Paladin should Hardin succeed in making his case. In that case, he will also carry one of the three keycards necessary to trigger Hidden Valley's self-destruct system for Render Unto Caesar, For the Republic, Part 2, and The House Always Wins.
↑The Courier: "Did you know Watkins and Stanton snuck out of here a few weeks ago?" Ramos: "Yeah, I knew about it. They're still young, and they weren't going to go very far. I had them on my monitors the whole time. I almost headed out there when they got surrounded by those scorpions, but Watkins is a hell of a shot." (Ramos' dialogue)