Trooper's journal

 is a book appearing in Deus Ex. It's the personal journal of a mercenary hired by MJ-12 to guard the Payens Cathedral.

Transcript
... don't know how I pulled this assignment. I was told that this was a "private security organization," but I should've known something was going on when they didn't ask about the damned discharge. Stupid. Now I'm walking the line at some gloomy ass church in the middle of Paris, nothing for company but a bunch of brain-dead zombies dressed in black and that crazy cook -- keeps rattling on about temples or templars and how he used to cook for the rich or something... I don't know. Food isn't all that great. Can't even get a bottle of ketchup. And then this German mech-aug shows up yesterday. I knew a lot of stone-cold people in the service, and this guy looks like he's got murder on his mind...

He stands down there in the tech archive like a bot -- I was on patrol in the cellar for 10 hours and he didn't move once. Inhuman. It's like he's waiting for something. I think I heard him crying once...