Maybe Mark saw something he wasn't supposed to, that night on the road.
Mark saw her several times, and eventually they had a long conversation in the woods.
Mark could see clearly now that his eyes had accustomed themselves to the dark.
Mark could see what was going on inside Louise's head.
If Mark saw the shot, he was supposed to take it.
Mark could almost see the wheels going around in the Chief's head.
Mark looked closer, and saw that she was absolutely correct.
Mark had never seen the old man behave in such a way before.
Otherwise, Mark would certainly have seen the possibility and said something.
Mark had not seen his mother eat three bites in two days.