Failed quest with Lester?

Lester ran away because he got angry with me, now I'm reading in the forums that he has a purpose? How do I get him back?

NK is really confusing. Now for some reason, I just killed an old man that showed up by the fire ruin. I know I asked him if he was Fargred, but he said he was going to kill me, so I had to kill him. Where did he come from? and I also have 2 papers that seem to belong to him.

Did you visit Keeper's Village? Some answers to your questions are there. Also, there is commonly more than one outcome when you engage in conversation with a character. Think about your answers and what consequences they might have. If you fail a quest with your answers (for instance fail to get Lester to join you) the game will tell you that you have failed the quest. Once you fail, there is no going back. 

I got a failed quest message when Lester ran away, so I guess that is it for that one. 

Now I know for the next time. 

Thanks