Explanation for ending of broken sword 1

This post contains spoilers of the game.

The whole game is about George and Nicole who try to find the broken sword. There is a group of people called Templars who also try to find the broken sword and one guy called Khan who tries to prevent them from finding it.

At the end, with a bunch of clues and a combination which is beyond my understanding, George and Nicole find the the place of the broken sword. Now here are some things that I simply don't get:

At the place where the broken sword is expected to be at, they also find the Templars. How did the Templars find this place? George only found it with a map and a lot of other thinks that were not reachable to the Templars, because George has stolen it.

Secondly, and more important, what was the broken sword? There were only a bunch of people worshiping a triple-face-idol and two stones with blue-storm-stuff. What was so scary about a triple-face-idol and blue-storm-stones that Khan wanted so desperately to prevent them from finding it? Also, during this ceremony they wanted to knight some random police officer. In this ceremony, someone who has a complete sword is talking about blacksmithing the old broken sword. However, I dont see a broken sword which becomes blacksmithed. I only see the Grand Master of the Templars gaining stormbolts from the blue stones.

I would appreciate if someone could explain me what this was all about.