Tribunal is an Morrowind Expansion Pack that will make you into a different world. Explore the Dwemer underground in the city of Mournhold. Meet the God named Almalexia that is a God of Mournhold and Morrowind, she will give you orders that is totally different. Sotha Sil is also a God of Morrowind that is master of machinery because of the machines that will looked like robots, those robots will attack you because they are protecting Sotha Sil, he was killed by his friend Almalexia because of the power of the hearth(you will know that in the history of Morrowind)
It is a place from the expansion pack. You can get there by the sorceress that will teleport you to Mournhold. You can buy epic items from the shops around the district. Buy and sell items at very high prices.
You see there are times when you are resting, there will be an assassin to attack you. They are called the Dark Brotherhood, you cannot join them as they are you enemies. As you earn levels, assassins will be stronger next time they attack.