After deciding on an approach, I surreptitiously clamber around the side of a ruin and go in for a silent kill. After taking out one enemy, I am almost immediately spotted by another. I jump from the ledge and hide in the tall grass until the enemy's curiosity fades. Just as the wary merc thinks all is well he turns and is taken out by Sam (Nate's brother), who I didn't even see coming. This kind of interaction occurred at least three more times during my short hands-on session with Uncharted 4 and each time I let out a quiet "wow" of amazement. Somehow, Naughty Dog has managed to balance the AI of Uncharted's NPCs so that they effectively aid the player, but don't completely take over the show. You still feel in control of the action.