Jaime

Background

The Vault Dweller will first learn of Jaime's existence upon entering the Dunwich Building and finding the first of his personal audio logs, which detail all of his adventures up to that point.

• According to the logs, Jaime was a traveler who, similar to the Vault Dweller, set out to look for his father after being left alone in a hospital and vanished into the wastelands on his own, apparently "going crazy" after receiving a mysterious book.
• Jaime followed his father far south across vast distances, albeit unwillingly, but his father was the only family he had in the ruins of the Capital so his pilgrimage was understandable.
• After meeting up with a group of fellow travelers he joined with them for a while, before realising they were violent raiders who were constantly raping and pillaging and killing.  One audio log mentions that they slaughtered an innocent for "a sack of rotten vegetables".
• Realising he was in danger, Jaime decided to try and get away at his first opportunity, which manifested in the form of an attack on a trader caravan.  Amidst the gunfire and confusion, Jaime slaughtered his raider comrades - earning the gratitude of the traders and removing himself from the hostile bandits once and for all.
• When Jaime spoke to the traveling merchants, they informed him of a man fitting his father's description heading far south towards a desolate building. While en route to the location they had pointed out, Jaime encountered snare traps that were similar to the ones his father used to catch food - so he must have found the right place.
• When he had been travelling with the raiders, they would tell spook stories of the old Dunwich Building, about zombies and monsters roaming its corridors.  Obviously these stories were a reference to the inhabiting ghouls which Jaime fought off continually as he searched the building for his father, eventully finding a ghoulified-yet-recognisable figure shambling around and clutching a book.
• Jamie's final legible audio log states that Jaime found his father.  Jaime makes a point of noting the "zombies" hadn't touched his father, or eaten him, but he had instead become one of them.  It is assumed at this point Jamie has killed his former father, he mentions that he isn't going to kill anymore, and mustn't forget the book his father had been carrying - it is all he has left of him. After this he mentions being tired, and his last words are said in an obviously ghoulish tone (I'll just rest a while).
  

Mutation

It's assumed at this point, the stone Jamie fell asleep against was the obelisk that the player finds Jaime worshiping in the basement with the other ghouls.  When Jaime awoke from his rest, he too was a mutated and radically insane ghoul.

The obelisk itself is of an unknown origin, not much is explained about the book Jaime is supposed to have repossessed (it isn't on his body or laying around). The obelisk is adorned with human skulls and has a strange carving of a a humanoid figure at its helm. Also when the player stands in the room near its vicinity, he will receive radiation poisoning, suggesting this is what is mutating the local ghouls and Jaime.
Spookily enough, whispers are heard all around the obelisk, even after the ghouls have been killed.

Appearance

Jamie in ghoul form hasn't quite degraded to the point of the skinless feral ghouls, his resemblance is far closer to that of the NPC ghouls which can be interacted with in the wastelands ( Gob in megaton for example).  There is no way to engage in dialogue with Jaime, and even with the ghoul mask on, Jaime will react with hostility towards the player the second he enters the vicinity, even though the other ghouls leave the player alone.

Audio logs 

There are 9 audio logs in all scattered about the building, each detailing Jamie's search leading up to the Dunwich Building, and then his experience inside:
 

Why the hell would he come all the way out here? Dad's been a little nuts for some time now, but not like this.

Leaving me in that crappy old hospital without waking me... without a goddamn flashlight.

I made enough selling the meds we scrounged to have kept us both fed at the colony for weeks.

Now I'm almost out of rations, my shoes are pretty much destroyed, and I'm still chasing the old coot. 
By my last reckoning, he was headed south.

Maybe I shouldn't have waited so damn long to start tracking him. Trail's gone cold. Going to wander with these guys a while.

They say they wander the area - maybe somebody's seen Dad.

These guys aren't who I thought they were. Jesus, they killed that family for a sack of rotten vegetables.

Getting out of here next chance I can without catching a bullet.

Hit a caravan today. Trev didn't see the kid and got popped. I took care of Tawny right then, and put one in Thor before he saw her fall.

That earned me some grub from the traders. Even better, they saw dad. He was in pretty rough shape, and still has the goddamn book.

Trader says it gave him the creeps. Me too. But it's good to know he's still alive. Still headed south.

He must have been trying to trap food here. I recognize his snares. I can make out a building on the horizon. That must be where he headed.

If not, at least I get a roof tonight.

Don't like the look of this place... don't like the smell. Gives me the creeps.

Don't want to risk a shot at the crows until I know what’s in there. Sneaking in tonight.

The Raiders told spook stories about zombies in the ruins. Never saw anything like that where I come from, but Lord help me, they're real.

Not quite what Thor said, but close. These things look... I think they really used to be people.

God help me. I found Dad today... I didn't think it was him, but... the face. The zombies didn't touch him. I think… he was becoming like them.

Didn't know it was him until I found that old book near him. No more killing. I just need to go. Can't forget the book. All I have left of him.

It's warm against the stone.(in an ghoul-like voice:) I'll just rest a while...

Sharp knife. Sharp knife to send him to deep temple. Flay and say my words. Abdul comes again, on the feast of the weaker. Feast for the Deep Temple.

Born again, here. Alhazzared G’yeth G’yeth.

Despite his "individualism", Jaime is relatively weak and will go down as easily as any other wastelander civilian.
He does carry a Chinese Assault Rifle, which is better than the standard Assault Rifle, and should not be left behind (even if it is just used to repair your existing one), he also has a finger for the player (if you have the lawbringer perk) and killing him nets you good karma.