To let a man enter your home, and then watch helplessly as he murders your family in cold blood, is more than any person should have to bear.
Now I can't even find the son-of-a-bitch to give him what he has coming. He kills my children in front of my eyes, and he gets to just walk away? No punishment, no justice? How is that fair?”— Dead end's author
According to the note, he killed the author's family in front of his eyes and let the author live who then started tracking him, seeking revenge.
Marko is mentioned only in Fallout 3.