After a short time walking down the road, a truck will start heading your way. If you need to get the following achievement, make sure you chose the 'Hide' option.
Get in the truck with Nate and he will eventually take you to a truck stop. Someone will start shooting at you. Follow Nates instructions and you will eventually head inside to sneak up on the person.
You need to make a decision on what to do with them. Once you have made that decision, you will get the achievement.