Tinker Tailor Stalker Spy:

I'm not a Loner. My name is not Kruglov. My task is to infiltrate any Factions that I choose, in order to investigate and seize any of the new prototype weapons and ammunition, that have illegally entered the Zone. I have left the Mercenary Faction to join the Loner Faction. I am the Stalker.
Encrypted Diary: The three-man Loner squad was a big help, in providing roving sentries and perimeter campfire watches.
* Game Note: