According to "Widescreen" magazine (Its sh*t, don't buy it), the "missing" TT trailer is an easter egg: "Angered by the lack of any sort of Two Towers preview on this special edition? Don't be. Peter Jackson has cunningly hidden the theatrical trailer of the Two Towers on disk two. This is the cut that was only shown at the end of FOTR's original theatrical run. It's very similar to the preview on the other Ring's dvd but now has a number of crucial changes. The running time is around 3 mins 50 sec. Where is it located? Try exploring the scene selections menu from beginning to end and look for any on screen graphics showing two towers, when you see these press enter on your remote and you should be away"