The mathematician feels guilty about an apparent suicide of a student that came to his office looking for help with some calculations in his thesis. The trail leads down a path to structural flaws in a prominent building.
Just when you think they are going to wrap everything up nicely and truly expose this suicide as the murder the mathematician thinks it is, the kid's suicide note shows up.
It was refreshing to see a network television program not wrap everything up in a neat little package. Sure, justice was done, the conscience of the mathematician's was salved, but this kid committed suicide for the reasons it was apparent that he would. It was good to see the writers not taking short-cuts on that.