A truly great movie.
The scene at the end where they are in the field, and Somerset opens the box and see's what's inside is a great cinematic moment.
All the more so because you do not see what is inside box...you don't need to. But the music strikes up this ominous, repeated chord that just grips you like a vice. The camera the starts whipping around between the three main protagonists and the tension becomes heightened.
Somerset knows what is going to happen, he knows's John Doe's masterplan and he must keep Mills from seeing what is inside the box...because he knows it will destroy him, and it will lead to an inevitable conclusion that John Doe is anticipating, and has indeed orchestrated from the very start.